An FBI whistleblower claims that the lead FBI agent on the Stevens case, Mary Beth Kepner, was having an affair with the prosecution’s star witness, Bill Allen, who admitted under oath to giving the longest-serving Republican senator some $250,000 in gifts that Stevens never disclosed on his Senate disclosure forms.

Stevens’ case is winding through the appeals process at the moment, on grounds of prosecutorial misconduct — separate from today’s revelations. If it’s true that Stevens’ conviction hinged on a sexual relationship between an FBI agent and an oil services company CEO, well, maybe it won’t matter that President Bush passed him over in the end.