The Parliamentary Commissioner for Standards yesterday submitted his report on John Prescott's controversial stay with Millennium Dome owner Philip Anschutz.
Sir Philip Mawer has been investigating whether there were any conflicts of interest in the Deputy Prime Minister's visit to the American billionaire's Colorado ranch in July last year.
He has now passed his report to the Committee on Standards and Privileges, Sir Philip's office said in a statement.
Sir Philip launched his inquiry after Tory allegations that the visit created a conflict of interest because Mr Anschutz was bidding to open a super-casino in the Dome.
He aimed to establish whether the stay should have been declared in the Register of Members' Interests.
The inquiry was later extended to look at gifts after it emerged that Mr Prescott had been given an elaborate cowboy outfit, worth several hundred pounds, by the US billionaire.
Yesterday's development came as Mr Prescott fell under renewed fire from Tory MPs in the Commons, where he was heckled with "Howdy" as he stood up to the Despatch Box.
In a rowdy exchange, Hammersmith and Fulham MP Greg Hands said: "Surely by giving such privileged access to one of the bidders, he has seriously compromised the whole bidding process for Britain's only regional casino?"
But Mr Prescott accused him of "reading too many press cuttings".
"I was not associated in any way with the planning of the Dome or the sale of the Dome and the decisions were taken in the department by other Ministers which I informed this House about," he said.
Mr Prescott brushed off resignation calls and rejected suggestions there might have been a breach of the Prevention of Corruption Act.