As government investigators look for the roots of Enron's demise, the chief executive who quit the firm months before it collapsed has broken his silence to deny any responsibility.

Mr Jeffrey K Skilling, who resigned as chief executive in August after a decade at the company, said in an interview with the New York Times that he had been stunned by Enron's subsequent descent and by revelations that his former chief financial officer made over $30 million (€33.8 million) from dealings with investment partnerships related to the company.

Mr Skilling said he had never invested in such partnerships and disputed assertions that he had been counselled against entering the company into deals with them. Mr Skilling helped transform Enron into the largest energy-trading firm in the world, but in October it disclosed huge losses partly because of dealings with investment partnerships involving Mr Fastow.