Ferrari have accused former technical manager Nigel Stepney of passing secrets to Formula One rivals after searching the house of a senior McLaren employee in England.
Championship leaders McLaren had earlier announced that their employee, who was not identified, had been suspended pending an investigation into the receipt of classified information.
"Ferrari confirm that we have brought an action against Nigel Stepney and a Vodafone McLaren Mercedes technical engineer in a court in Modena regarding the theft of technical information," said a spokesman for the Italian team.
Stepney, who has accused Ferrari of waging a dirty tricks campaign against him and denied any wrongdoing, fell out with Ferrari after the departure of technical director Ross Brawn at the end of last year.
McLaren said they found out only on Tuesday of the involvement of their employee.
"McLaren became aware on July 3, 2007 that a senior member of its technical organisation was the subject of a Ferrari investigation regarding the receipt of technical information," they said in a statement.
"The team has learnt that this individual had personally received a package of technical information from a Ferrari employee at the end of April.
"Whilst McLaren has no involvement in the matter and condemns such actions, it will fully co-operate with any investigation," it added.
SEARCH WARRANT
A spokesman for Formula One's governing body, the International Automobile Federation (FIA), said they are looking into the case.
McLaren are leading Ferrari by 25 points in the constructors' championship after eight races, with the British Grand Prix at Silverstone being held on Sunday.
Ferrari won in France last weekend, ending a run of three McLaren victories.
The McLaren employee was suspended after Ferrari, who announced earlier on Tuesday that they had dismissed Stepney, took legal action in England and obtained a search warrant.
"A search was carried out of the [McLaren] engineer's house, where we found this information," the Ferrari spokesman confirmed.
Stepney, who is on holiday in the Philippines with his partner and child, made clear in February that he was open to offers from other teams. Ferrari subsequently moved him away from the racetrack operations.
Ferrari sources said that a significant amount of classified information is involved in the case and they are not ruling out other teams having also received some.