A former senior executive of the bankrupt US energy giant Enron has committed suicide.

Until the middle of last year Clifford Baxter was vice chairman of Enron and the firm's chief strategy officer. He resigned in May to "spend additional time with his family", but stayed on with the firm as a consultant.

Police in Sugar Land - a suburb of Houston, Texas - said Mr Baxter had been found in his car with "an apparent self-inflicted gunshot wound to the head". A suicide note was found, but its content not disclosed.

Mr Baxter, 43, was one of 29 former and current Enron executives named as defendants in a federal law suit.

Enron began to collapse in October last year, brought down by huge debts and accusations of accounting irregularities.

It filed for bankruptcy protection in December, after admitting that it had hidden huge losses from its books.

The Enron collapse has also become a political story because of the company's close links with the White House.

On Friday the White House said it had ordered a review of all US government contracts with Enron and its auditors Arthur Andersen to ensure "a satisfactory record of business ethics and integrity."

Share deals

Mr Baxter's role in the Enron affair is unclear. He was named in a letter written in September by an Enron whistle-blower Sherron Watkins, who suggested that Mr Baxter had clashed repeatedly with former chief executive Jeff Skilling over the firm's practice of hiding millions of dollars in debt in dubious deals with so-called shell companies.

Ms Watkins said she was stunned at the news of Mr Baxter's death, saying he had "the utmost integrity" and that she "respected him immensely."

Further attention was focused on Mr Baxter after it emerged that he sold nine million dollars worth of Enron shares between January and August 2001.

Many Enron executives have been accused of cashing in their stock options before the firm's share price crashed.

The majority of employees were prohibited from selling their shares, and many of them say they have lost all their savings and pensions provisions.

Under investigation

Enron issued a statement saying "we are deeply saddened by the tragic loss of our friend and colleague".

The Houston-based energy trading firm has become the focus of a criminal investigation and almost a dozen Congressional inquiries since it collapsed at the end of last year.

Mr Baxter's death comes a few days after a Congressional committees subpoenaed several senior figures from Enron's audit firm Andersen to give evidence.

John Clifford Baxter was born in 1958 in Amityville, New York. He studied science at New York University, and in 1987 received an MBA from Columbia University. He was a captain in the US Air Force between 1980-85.

In 1991 he joined Enron. Moving swiftly through the ranks, Mr Baxter became chairman and chief executive of Enron North America, before joining the firm's top echelon in June 2000.

When he left the company, the then-chief executive of Enron, Jeff Skilling, praised his "creativity, intelligence, sense of humour and straightforward manner".

Captain David Marcaurele, Texas Police: "We have no evidence to suggest it is anything other than a self-inflicted gun shot wound"

Washington Post journalist, Dana Milbank: "There was no immediate suggestion that he was involved in wrongdoing"