Former Enron chief financial officer Andrew Fastow took the witness stand today at the trial of ex-Enron CEOs Jeffrey Skilling and Ken Lay.
Mr Fastow (44) is the highest ranking witness to testify against the two executives, who together face more than three dozen charges of conspiracy, fraud and insider trading linked to the collapse of the company into bankruptcy in December 2001.
His intimate knowledge of Enron's finances and close contacts with Mr Lay and Mr Skilling during his tenure at the company, which was once the nation's seventh-largest, are likely to make him the star witness in the trial, now in its sixth week.
The former CFO, whose wife served a one-year jail term for tax fraud, has pleaded guilty to two counts of conspiracy to commit fraud and will serve a 10-year sentence under an agreement with the government.
Mr Lay and Mr Skilling have denied they took part in any crimes at the company and have blamed Mr Fastow for the company's implosion.
In his January 2004 plea agreement, Mr Fastow wrote that he and other members of Enron's senior management manipulated the company's financial results to mislead investors and artificially inflate Enron's stock price.
Enron's dramatic fall into the largest US bankruptcy of its time in December 2001 was the first in a wave of scandals that rocked financial markets and led to the adoption of stricter disclosure laws.