Max Mosley, the president of the FIA, sent a shiver down Formula One's collective spine yesterday by making it clear that he believes that the scandal that disgraced him was organised by his enemies within the sport. What is more, Mosley is quietly confident that private detectives working on his behalf will gather the evidence required to name names in allegations that could cause the biggest eruption in Formula One's long and turbulent history.

Mosley, speaking before this weekend's Italian Grand Prix, used his first return to the paddock since a brief appearance in Monaco at the end of May, to load the gun, even if he was not able to say at whom he was pointing it. From the moment that the News of the World published lurid details in March about his penchant for sado-masochistic orgies with prostitutes, Mosley has believed that he was the victim of a set-up and that his downfall was not the result of one prostitute and her husband trying to make some money.

“The fact that Lord Stevens is quiet doesn't mean he's not working,” he said in reference to Lord Stevens of Kirkwhelpington, the former Metropolitan Police Commissioner, whose private investigation agency is working for Mosley. “I believe there is much more to it than that one lady,” he added, alluding to the prostitute who has admitted selling a video of Mosley in a Chelsea “sex dungeon” to the newspaper.

Asked who he believes is behind the conspiracy, Mosley said: “It's not from my private life world. I think it's most likely to be something to do with motor racing.” He confirmed that he was referring to Formula One and said that it may take a few more months to gather the evidence.

Mosley's comments will reignite the speculation in the paddock about who may have set out to destroy him. Several people, among them Ron Dennis, the team principal of McLaren Mercedes, and Bernie Ecclestone, the sport's commercial rights-holder, have denied having anything to do with a plot against the FIA president.

Mosley arrived in Monza in ebullient mood and showed no sign of embarrassment about his conduct. He vigorously rejected suggestions that he should have resigned because of the scandal as so out of date that they were of a 19th-century moral vintage and dismissed The Times and the Daily Mail, who have been among his harshest critics, as the “gutter press”. He also attacked George Carey, the former Archbishop of Canterbury, who has criticised what he called Mosley's “unspeakable and indecent behaviour”, as that “silly old archbishop”.

The FIA president said that he is receiving messages of support from association members who want him to stand for another four-year term when his mandate ends in October next year. “This sounds boastful - I'm receiving requests to stay on after 2009,” Mosley said. “They are coming from all over the world, genuinely. That means there is a perception I might [stay on]. At present it's my firm intention to stand down, but you have to take account of what people say.”

On the row over the penalty handed down to Lewis Hamilton by FIA stewards after the Belgian Grand Prix at Spa-Francorchamps last weekend, which demoted the McLaren driver to third place and is the subject of an appeal to be held on September 22, Mosley denied that there was any bias against Hamilton or his team. He said that such suggestions were “absolute nonsense - it couldn't be more nonsensical”. He argued that it was only Hamilton's supporters and the British press who took this view, which he called a collective hysteria.

The credibility of Alan Donnelly, the FIA chief steward, has been called into question amid revelations about his former business dealings with the Ferrari manufacturing division of road cars. Mosley was adamant that Donnelly should not be removed and said that it was ridiculous to argue that he would be biased in favour of Ferrari.

“I do believe it is complete and utter rubbish and, particularly in Formula One, it would be impossible to find somebody who had a reasonable knowledge of [the sport] who hadn't had a relationship with one of the teams,” he said.

On the track, the first session of Friday practice ended in a washout in driving rain. In the afternoon with dry running, Kimi Raikkonen, of Ferrari, celebrated the announcement that he is to remain with the Scuderia until the end of 2010 by topping the timesheets ahead of Robert Kubica and Nick Heidfeld, the BMW Sauber drivers. Hamilton was fourth fastest, while Felipe Massa, his main championship rival and Raikkonen's team-mate, was sixth.