Former Enron chief executive Jeffrey Skilling has insisted to sceptical politicians that he knew of nothing improper about the web of partnerships that brought down the company.
Four of Skilling's former colleagues at the energy-trading conglomerate remained silent and refused to testify to the House of Representatives subcommittee, invoking their constitutional privilege.
Mr Skilling testified under tough questioning in his first public accounting of the collapse.
Back in August, when he resigned his post, "I did not believe the company was in any financial peril," he said. "I absolutely, unequivocally thought the company was in good shape."
The company's financial statements, "as far as I knew, accurately reflected" Enron's condition, Mr Skilling told the House Energy and Commerce oversight subcommittee.
He said he had no knowledge that the partnerships run by his long-time colleague Andrew Fastow, who collected at least $30m for his efforts, were designed to conceal massive losses.
Mr Skilling spoke after Mr Fastow and three other current or former Enron executives declined to answer questions at the hearing, citing their Fifth Amendment right against self-incrimination.
Mr Skilling, who resigned before Enron's troubles became public, insisted he did not know the details of the partnerships that concealed hundreds of millions of dollars in debt and overstated the company's profits by more than $1bn over several years.
Mr Skilling also said he could not recall key events under close questioning by members of the subcommittee.
In contrast to Mr Skilling's statements, Enron's new president and chief operating officer, Jeffrey McMahon, testified earlier he was transferred to a new job shortly after he complained to Mr Skilling about the obscure partnerships.