Lewis Hamilton’s chances of becoming the Formula One world champion in his rookie season were again under threat last night after new evidence emerged that his team, McLaren Mercedes, may have used Ferrari technical secrets on their cars.

The latest blow to McLaren came in a statement from the FIA, the governing body of motorsport, which said that it had received new evidence in connection with the long-running spy scandal and that its World Motor Sport Council (WMSC) will sit to consider it in Paris a week today.

The FIA did not say where the new evidence had come from and a spokesman refused to comment. However, there were suggestions that it did not come from Ferrari or sources in Italy, leaving open the possibility that other rivals of McLaren may be involved.

The FIA had been planning to hold a session of its Court of Appeal next Thursday, at which Ferrari were going to be given the chance to contest a decision by the WMSC not to punish McLaren over the possession of Ferrari technical information by Mike Coughlan, the chief designer. This hearing has been cancelled.

In that judgment in late July, the WMSC found that, although McLaren had the information – thought to be a 780-page dossier with details of Ferrari’s present cars, their racing operations and design effort – there was insufficient evidence that it had been used on the racetrack.

However, the council left open the possibility of what amounts to a “retrial” if new evidence emerged. In its judgment, it said: “We reserve the right to invite Vodafone McLaren Mercedes back in front of the WMSC, where it will face the possibility of exclusion from not only the 2007 championship but the 2008 championship.”

That this has come to pass is a setback for McLaren, Hamilton, Fernando Alonso, his teammate, and Ron Dennis, the team principal, who has argued passionately that any team run by him would not use information stolen from rivals and that none of the data in Coughlan’s possession had “contaminated” McLaren’s campaign.

In a statement last night, McLaren said that they were aware of the decision of the FIA and that they would continue to cooperate with the governing body. “McLaren Racing has been made aware that new evidence has been presented to the FIA. As a result we have been informed that the Court of Appeal hearing will now comprise a meeting of the WMSC.”

The big worry for the Woking-based team is that the FIA and its president, Max Mosley, would not have taken the decision to reconvene the WMSC, which involves flying 26 members to Paris from all over the world, had it not been given evidence that it regarded as serious. Also on the collective mind of the WMSC – although the FIA would deny this – will be the withering reaction from Ferrari to its initial decision, which the Italian team described as “incomprehensible” and “legitimising dishonest behaviour in Formula One”.

In Italy, a prosecutor has claimed that Nigel Stepney, the disaffected English former Ferrari mechanic who is alleged to have supplied Coughlan with the dossier – he denies it – is also linked to an attempt to sabotage Ferrari’s cars before the Monaco Grand Prix in May.

Ferrari are taking legal action against Stepney over allegations, which he denies, that he used a powder to contaminate the petrol in their cars. Giuseppe Tibis, a prosecutor in Modena who has completed his file on the case, said yesterday: “Certainly from sworn testimony the suspicion exists that it was Stepney who handled the powder that has polluted the petrol.”

The latest developments come at a critical time for Hamilton as he prepares for the Italian Grand Prix in Monza this weekend and the Belgian Grand Prix in Spa a week later, with the hearing in Paris sandwiched between them.

Hamilton has a five-point lead over Alonso with five races to go. He and the team, who have been trying to heal the internal wounds over the rift between their two drivers, will have to maintain their focus, despite what decisions are reached in Paris.

While McLaren continue their battle with Ferrari in court, they will also have to keep a close eye on them on the track. The Scuderia have recaptured their early-season form and, after a one-two for Felipe Massa and Kimi Raikkonen at the Turkish Grand Prix last month, will be looking to produce another strong performance at their home race in Monza.