Kenneth Lay, the former Enron chief executive and chairman convicted on fraud and conspiracy charges, has died.

Mr Lay suffered a heart attack at his holiday home near Aspen, Colorado. He was pronounced dead in hospital shortly after 0300 local time on Wednesday.

He and former chief executive Jeffrey Skilling were found guilty in May in connection with Enron's collapse.

Enron went bankrupt in 2001 with debts of $31.8bn (£18bn), leaving 4,000 people out of work.

Innocence maintained

After America's most high-profile corporate fraud trial, Mr Lay was found guilty on 25 May on all six fraud and conspiracy charges that he faced.

He had posted a $5m bond to avoid custody until October when he would have been sentenced - to up to 45 years behind bars.

Mr Lay had always proclaimed his innocence, saying the company was brought down by a lack of investor confidence triggered by revelations that Enron's chief financial officer Andrew Fastow had stolen millions from the company.

He described Enron's collapse as "the most devastating and heartbreaking tragedy of my life".

The 64-year-old had led Enron for 15 years from its birth in 1986 after the merger of two Houston-based gas pipeline firms.

From this small beginning, Enron went on to become America's seventh biggest company and the world's largest energy trading firm.

Mr Lay handed the chief executive's role over to Jeffrey Skilling in 2001.

Mr Skilling was convicted on 19 counts of fraud and conspiracy and is expected to face a lengthy prison term.

'Reports pending'

As well as bringing down Enron and its former bosses, the scandal had a far-reaching effect on corporate America, prompting a re-evaluation of company values and governance.

The Enron scandal, along with the collapse of phone firm Worldcom, was the driving force behind new legislation that holds executives responsible for what happens at the companies they work for.

Today it is no longer enough for chief executives to say they did not know what was happening at their firms.

According to reports, Mr Lay was taken by ambulance from his holiday home in Old Snowmass, Colorado, on Wednesday morning and driven to Aspen Valley Hospital.

He was pronounced dead shortly after 0300 local time (0900 GMT).

"A coroner's autopsy is pending," a county official said. "There will be no further information or press release from this office until autopsy results are available later this week."

Mr Lay is survived by his wife, Linda and five children and step-children.

THE ENRON SAGA IN FIGURES
$101bn: Enron's claimed revenues in 2000
$31.8bn: The size of Enron's debts when it went bankrupt in 2001
$252m: The amount, including stock options, that Kenneth Lay earned in his best year at Enron
$100m: Mr Lay's peak personal debt. "It was difficult to turn off that lifestyle like a spigot," he once said
$75m: The sum Mr Lay spent on shares illegally bought using bank loans - he said he did not remember having been told that it was against the law
$40m: Mr Lay's overdraft facility
$23.8m: The fine paid by Andrew Fastow, the former Enron chief financial officer who pleaded guilty to fraud in 2004 and is serving a 10-year jail sentence
$200,000: the cost of hiring a yacht for Mr Lay's wife Linda's birthday party.

A body found in north-east London has been identified as that of a banker who was questioned by the FBI about the Enron fraud case.

(Police said the body was found on the ground by a walker.)

Police said they were treating the death in Chingford of Neil Coulbeck, who worked for the Royal Bank of Scotland until 2004, as "unexplained".

He had been interviewed by the FBI as a potential witness.

Three ex-workers of RBS subsidiary NatWest are being extradited to the US on Thursday to face fraud charges.

The extradition has sparked a political row, with opposition parties and human rights groups claiming the treaty under which they are being sent to the US is one-sided as the Americans are yet to ratify it.

'Highly regarded'

Prime Minister Tony Blair has rejected calls to renegotiate the extradition terms.

Mr Coulbeck's body was found in a park near Newgate Street, Chingford, on Tuesday.

Mr Coulbeck's wife had reported him missing last Thursday. Police have yet to formally identify the body, which was removed from the parkland on Wednesday afternoon.

Mr Coulbeck had worked at the Royal Bank of Scotland until 2004, most recently as head of group treasury, the bank confirmed.

"Neil was highly regarded by his colleagues here in RBS and was a respected, capable and hard working member of our senior management team."

The fraud case centres on a NatWest transaction under which it sold off part of its Enron unit.

RBS said: "There is no evidence that Mr Coulbeck was involved in the approval of the transaction under investigation.

"RBS has co-operated fully with all the appropriate authorities and made them fully aware of all the relevant facts in our possession."

The FBI said it would not comment while the case was ongoing.

'Appalling'

One of the so-called NatWest three, David Bermingham, said he had been "knocked sideways by the news" of Mr Coulbeck's death.

"It is awful, appalling. One day when this is all over I'm going to be coming home to my wife and children and some poor guy is not and my heart goes out to his wife and family," he said.

He described Mr Coulbeck as "a superstar, a thoroughly decent, honest professional guy and a very experienced banker".

(L-R) Giles Darby, David Bermingham and Gary Mulgrew
The former NatWest executives deny any wrongdoing

Mr Coulbeck was among NatWest staff who made witness statements about the extradition, Mr Bermingham, of Goring, Berkshire, said.

"Neil's statement was no more than a page and a half saying who he was and his role," he said.

Fellow accused Giles Darby, speaking from his home in Lower Wraxall, Somerset, said he was "absolutely shocked" by the death.

"It's an utter tragedy. I'm struggling to take it in, really.

"Of course, my thoughts are now with Neil's family and friends."

In 2002, US prosecutors issued arrest warrants for the three men, accusing them of conspiring to defraud their employers and investors in energy giant Enron, which had collapsed a year earlier.

It is alleged that the three British bankers - Mr Bermingham, Gary Mulgrew and Mr Darby - advised their employer Greenwich NatWest to sell off its stake in an Enron unit at well below its market value.

MPs' protest

They then left the bank and purchased a $250,000 (£135,000) stake in the unit - which they sold on at a much higher price, making a profit of $7.3m (£3.9m).

They deny any wrongdoing.

Their extradition was debated by MPs in an emergency session of Commons on Wednesday.

After a three-hour debate they voted by a majority of 242 to adjourn the Commons early in symbolic protest at the government's extradition arrangements.

On Tuesday, peers had voted in favour of suspending extradition agreements with the US until the UK-US treated had been ratified there.

Three former NatWest bankers extradited to the US on fraud charges arising from the Enron collapse have been bailed.

The men were released until next Friday but on the condition that they are tagged and remain in Houston. They all pleaded not guilty to the charges.

David Bermingham, Giles Darby and Gary Mulgrew will hear the full conditions of bail on 21 July. Their lawyers have argued they should return to the UK.

Their extradition has sparked a row in the UK over US powers to extradite.

Legal costs

As well as being electronically tagged and having their passports taken away, the three men - dubbed the NatWest Three - had to pay sums of cash to secure their freedom.

While Mr Bermingham and Mr Darby each posted bail of US$100,000 (£54,400), Mr Mulgrew put up US$20,000 plus shares in Glasgow Celtic football club.

Each man's lawyer made the case at Friday's hearing that they must be allowed to return to England to work in order to support their families and pay for legal costs.

Their defence case could take as long as two years to prepare.

But the prosecutor opposed their return to England, saying it could mean further extradition proceedings.

'Probable cause'

Prosecutors say that in 2000, the three men advised their former employer NatWest to sell part of a company owned by collapsed US energy giant Enron for less than it was worth.

They then left the bank and bought a stake in the company before selling it on at a significantly higher price, and making a huge profit, it is claimed.

They have been fighting extradition since they were arrested in 2004.

They say that extradition laws are unfair because the Americans have yet to ratify a treaty between the two countries.

The US only needs to outline an alleged offence and provide "evidence or information that would justify the issue of a warrant for arrest in the UK".

But British police must provide American courts with evidence of "probable cause" if they wish to extradite someone.

Mr Darby, from Lower South Wraxall in Wiltshire, Mr Bermingham, from Goring in Oxfordshire, and Mr Mulgrew, from Brighton in East Sussex, are accused of defrauding NatWest of over £1m each.

If they are found guilty, they face up to 35 years in jail.

The wife of one of the extradition row NatWest Three said she feared the men would face financial ruin if they were not allowed to return to Britain.

Emma Bermingham said none of the men had the means to support themselves financially if they were forced to remain in the US until their trial, which could take up to two years to prepare.

Mrs Bermingham's husband David, Gary Mulgrew and Giles Darby have been bailed by a court in Houston, Texas, but will have to wait another week to find out if they can return to Britain.

She said Mr Darby and Mr Mulgrew both had businesses which would be difficult to maintain if they were prevented from travelling home.

If the judge forbids them to return full-time, Mrs Bermingham said they would ask to be allowed to spend a fortnight each month in Britain.

She said: "All the witnesses, documents and evidence is over here. It would be great if they could spend time with their families and also do a bit of work.

"Gary and Giles have both got companies. If they could come back to the UK for a fortnight at a time they could manage to keep an income."

Speaking from her home in the Oxfordshire village of Goring, Mrs Bermingham, 39, said if they were refused permission to come home it would be better if they were held in an open prison rather than having to support themselves until their trial.

She said at the moment all three men were staying at the home of her husband's lawyer Dan Cogdell.

The men deny making more than £1m each out of an alleged fraud against their former employer, NatWest. They each face a maximum of 35 years in prison if convicted of all the charges against them.

No, I'm not thrilled over Jeffrey Skilling getting 24 years in prison for his role in the Enron scandal. While he and fellow Enron honcho Kenneth Lay were clearly guilty as charged, the handling of this case by the Bush Justice Department is a functional coverup of the Bush family's role in enabling these crimes.

The thousands of Enron employees who lost their jobs, as well as $2 billion in pension money and $60 billion in share value, deserve better. By focusing on narrowly drawn criminal charges and the public's wrath against Skilling and his late partner in crime - "Kenny Boy" Lay, as President Bush referred to his onetime chief campaign benefactor - the culpability of the president's family in this sordid saga is being whitewashed.

How convenient to close the book without considering the ties between the Enron perps and those in two Bush presidencies whose actions enabled these hustlers. The Enron crooks would never have been more than petty thieves were it not for the political support they received from their fellow Texas oil buddies. They knew that, and they paid for it: Over the years, Lay and Enron gave the Bush family politicians $3 million in contributions, as well as lending the campaigning George W. a jet on at least eight occasions.

They did so because, without the deregulation of the energy industry pushed by the first President Bush, Enron would have remained a minor company without the capacity to swindle. At the time, Lay wrote a column supporting the elder Bush's reelection by praising him as "the energy president" because "just six months after George Bush became president, he directed ... the most ambitious and sweeping energy plan ever proposed."

Specifically, Enron benefited mightily from a key ruling by Wendy Gramm, head of the Commodity Futures Trading Commission under George H.W. Bush, permitting Enron to trade in highly profitable energy derivatives. A mere five weeks after rendering that ruling, Gramm, the wife of then-Sen. Phil Gramm (R-Texas), abruptly resigned to join the Enron board of directors, where she served on the company's now-infamous see-no-evil audit committee. Secretary of State James Baker and Commerce Secretary Robert Mosbacher also rushed to work for Enron after their White House tenures.

Dubya first got involved with Enron's Lay when they both worked on his daddy's campaign, and the relationship flowered during his years as the governor of Texas. There is, in fact, a long paper trail of "Dear Ken" and "Dear George" exchanges that have come to light, thanks to Freedom of Information Act requests. The correspondence exposes the active support given by Bush to Enron's expansion into markets ranging from Uzbekistan to Pennsylvania. As Lay wrote to Bush in a letter dated Oct. 7, 1997: "I very much appreciated your call to Gov. Tom Ridge a few days ago. I am certain that will have a positive impact on the way he and others view our proposal."

In payback for Bush's support, Lay became a Bush "pioneer" fundraiser, dumping in more than $2 million in contributions from himself and Enron executive funds. Lay's influence with Bush extended well into the first year of the Bush administration, when Bush stonewalled California while it was being extorted through a manufactured "power crisis" by Enron and other energy companies to buy energy at grossly inflated prices.

The Enron boss also became a principal architect of the new Bush energy policy in the months before his downfall, completely undermining the spirit of democracy. In fact, the public has still been denied access to the six secret conversations Lay had with Vice President Dick Cheney when the vice president was quarterbacking the Bush administration's response to the California energy crisis, which saw the prosperous state preposterously hit by rolling blackouts. Lay provided Cheney with a key memo opposing price caps that would have mightily aided California consumers.

Lay also played a major role in the dismissal of Curtis Hebert Jr. as Federal Energy Commission chairman. Hebert was too independent for Enron's taste, while his replacement was far more amenable to the company's agenda.

Without the specific energy policies pursued through two Bush presidencies, Skilling and Lay would have remained two-bit Texas hustlers going nowhere fast. But thanks to their presidential sponsors, who in turn received lavish campaign contributions, the biggest corporate swindle in U.S. history was allowed to unfold.

Why were the dots between the Enron swindlers and their government sponsors never connected by a Bush Justice Department that seemed more interested in containing the damage than exploring the true ramifications of this case? Getting to the bottom of this story is one compelling reason to hope that the Democrats gain control in this election of at least one branch of Congress, thus permitting a serious investigation of the political machinations behind the Enron swindle.