The FIA began its investigation into the McLaren 2008 car this week, in line with the World Motor Sport Council's decision in the spying affair.
The governing body excluded McLaren from the 2007 constructors' championship after confidential Ferrari information was leaked to McLaren's then chief designer Mike Coughlan.
McLaren had since suspended Coughlan, but the WMSC said in its September verdict that it would make a decision on whether or not to further penalise McLaren for the 2008 season after an examination of the 2008 cars take place.
Investigators on behalf of the governing body visited the McLaren Technology Centre in Woking in the last couple of days, where they reportedly held a thorough examination on the premises and took with them data for further analysis.
Asked about the investigation, a McLaren spokesperson told autosport.com: "We are unable to make any comment other than to say that an inspection has always been part of the WMSC decision, and of course we are cooperating fully with the FIA."
According to sources, the FIA has forbidden McLaren to reveal details of the probe. The governing body also said it would not comment due to the fact that it is part of an ongoing investigation.
FIA president Max Mosley last week revealed the governing body will likely use third-party experts to review the data collected on the McLaren 2008 car.
"The investigation will be thorough," he told the BBC, "it will use outside experts and we will do everything we possibly can to make sure that either of the McLarens has no element of Ferrari intellectual property in it.
"If it does, we will then have to consider taking some sort of action."
Mosley said, however, that McLaren would not necessarily be excluded again from the championship.
"That would not necessarily be preventing them from running," he said. "It would be more likely that they would be given a negative point allocation."