Investigators of the Enron collapse have told the BBC that they do not believe Lord Wakeham was party to any fraud at the centre of the scandal.

Congressmen leading the investigation say they do not think the Conservative peer - an Enron director and audit committee member - knew about the attempt to hide debts from shareholders.

But he could still face lawsuits for hundreds of millions of dollars from those who accuse him of failing to make public concerns about the energy giant.

Mountain of documents

The investigation comes to a climax this week with hearings in Washington.

But senators leading the highest-profile investigation said they have not seen any evidence in the mountain of documents before them of wrongdoing by Lord Wakeham.

They believe he did not know about what was in effect a pyramid scheme where huge sums were borrowed on the strength of non-existent assets.

But senators added that there remains the question of whether he ought to have known and said so publicly.

No criminal charges

A legal document filed in a Houston court said "defendant Wakeham... knew or should have known but failed to disclose to Enron's current and former employees that concentrated investments in company stock were imprudent".

Separately, UK and US authorities have been asked to decide whether Lord Wakeham should be barred from being a company director for not blowing the whistle before the bankruptcy.

Lord Wakeham declined to comment.