Khan, 25, used his Twitter account last week to post a series of images of a mystery man, seen wearing a dark hat and apparently attempting to influence the judges, who eventually awarded the fight - and the Briton's WBA and IBF light welterweight titles - to Peterson in a disputed split points decision.
Mystery man: Ameen points at papers held by WBA fight supervisor Michael Welsh
Bruising: Amir Khan in action against Lamont Peterson last month
On Saturday, the man at the centre of the mystery was named by Khan's promoters, Golden Boy Promotions, as an IBF official, Mustafa Ameen. He is understood to have been accredited to attend the fight but is alleged to have had no authorised role.
Ameen was seen in video footage brought to worldwide notice by Khan sitting close to the judges, handing paper to one of them and speaking to WBA supervisor Michael Welsh.
Khan was incredulous when the fight and his titles were awarded to Peterson in a verdict heavily influenced by referee Joe Cooper's unprecedented decision to deduct points from Khan for pushing his opponent.
Now Richard Schaefer, chief executive of Golden Boy Promotions, has insisted that the WBA have told him they will order a rematch of the fight.
Name revealed: Mustafa Ameen seen after the fight in Washington
Schaefer said: 'We have been informed today by the WBA that they will order an immediate rematch. We received a verbal confirmation today and we will get a written confirmation by next Tuesday.
'That means that no fighter can take an interim fight, that the next fight for Peterson would be a rematch.
'We hope that the IBF will follow because that's the least they can do. The ruling of the WBA to order an immediate rematch should put additional pressures on the IBF.
'The IBF have confirmed to us that the man at ringside in the hat is Mustafa Ameen and they have confirmed to us that he's involved in an official capacity with the IBF.
Controversy: Khan lost to Peterson on points
'However, he was not in Washington in an official IBF capacity, but the IBF asked the Washington commission to issue him accreditation so that he could attend the fight.'
Schaefer is campaigning for the outcome of the fight, which was staged in Peterson's home city, to be changed to 'no contest' - an outcome that would allow Khan to retain his belts. 'I certainly hope this can happen,' said Schaefer.
After originally agreeing to a rematch on the night Khan lost, Peterson's management have since had a change of heart and turned down an £800,000 purse to fight the Briton a second time.
Khan's willingness to defend his titles in the US capital, where Peterson grew up as a street orphan in a crime-ravaged neighbourhood, has taught him that in boxing the hardest fight is not always inside the ring.
Schaefer said yesterday: 'You cannot go out and accuse people of things, but there are a lot of question marks and these questions need to be answered.'
The IBF have insisted that they will not comment until they have heard Khan's appeal against the result in Washington in 10 days' time.
Ameen, business manager for US heavyweight Michael Hunter, was defended yesterday by a friend, who said: 'This guy has been around the boxing world for decades. There is no way that he would fix a fight. It would cost him his reputation, everything. There has got to be a logical explanation of what happened with the Khan fight.'