Coughlan admits telling others about secrets
Italian newspaper La Repubblica reproduced excerpts of the document, which as part of a private agreement with Ferrari cannot be used by Italian prosecutors in a case against the suspended engineer.
But, if it is the truth, the signs are not good for Woking based McLaren, which has so far insisted that only chief designer Coughlan knew about the sensitive information that was in his possession earlier this year.
"It's true," Coughlan reportedly wrote in his sworn statement. "I had all the designs.
"It was my responsibility. I showed those designs to McLaren and not just to (managing director) Jonathan Neale but to others as well.
"Everyone reacted the same way and told me to get rid of them."
At an emergency World Council meeting later in July, the FIA will question McLaren about its involvement in the espionage saga. Possible sanctions range from docked points and race bans to total exclusion from the world championship.
Coughlan did not confirm that Ferrari's Nigel Stepney sent him the material, explaining that he received the package from a courier mail service.