Formula 1 teams signing FIA personnel risks creating mistrust, fears Sauber team boss Frederic Vasseur, who says recent Ferrari signing Laurent Mekies knows 'key details' of every new car.
Renault's ex-FIA F1 technical director Marcin Budkowski is due to begin working with the grand prix team soon, while FIA safety director Mekies will switch to Ferrari later this year.
Budkowski's move triggered anger among other F1 teams amid fears his knowledge transfer means Renault will soon understand the inner workings of their technical packages.
News of Ferrari hiring Mekies then provoked fresh outrage over a supposed gentlemen's agreement struck over the amount of 'gardening leave' FIA staff would have if they left to join a race team.
Vasseur told Autosport: "It's a shame that we are not in the situation that the FIA could find a solution to keep their key guys.
"I remember perfectly the situation with Marcin, he was in all the windtunnels two weeks before he left.
"Laurent is aware of key details of every single car, even if he was more focused on safety he's aware of the key structure.
"At one stage, if we can't trust them it will be an issue because we need to be very open with the FIA.
"We need to ask them if we're in the regulations or not. If we are scared about this, it will be the beginning of a mess."
The Mekies signing, and the supposed agreement it breached, was a hot topic over the opening weekend of the F1 season, particularly when Red Bull boss Christian Horner clashed with Ferrari's Maurizio Arrivabene in the pre-race press conference.
Force India chief operating officer Otmar Szafnauer said: "The time between leaving the FIA and starting at Ferrari should have been increased to at least a year.
"It's difficult to stop people from moving from the FIA to teams but that time you have to sit out should be big enough to where you can't take intellectual property from one team because you have a privileged position at the FIA to another. That's not fair."
Ferrari supposedly led the push for a stricter agreement but swooped for Mekies before that was enshrined in anything legally binding.
Szafnauer added: "I wonder what that says about gentlemen?
"He [Ferrari chairman Sergio Marchionne] was vociferous about it. I'll have a discussion with him it at the next [meeting]."