Toro Rosso found itself in hot water Thursday at Silverstone when it presented Carlos Sainz car to the Stewards at scrutineering.
A damaged wheel tether was found on the #55 STR12, but when the Stewards requested the component to be replaced, the team refused.
"During initial scrutineering car number 55 was found to have a damaged wheel tether," read a note released by the FIA's technical department.
"The scrutineers made the team Scuderia Toro Rosso aware of this and asked the team to replace it.
"The team refused to follow the instructions of the scrutineers and therefore the technical delegate checked the damaged tether himself and found that the tether was not only damaged but also several cut fibres were knotted together.
"Therefore the team was aware of the damaged tether and presented the car in an unsafe condition for scrutineering."
Toro Rosso's attempt to enter the car is a breach of Article 12.1.1.b of the FIA's International Sporting Code, which states it is an offence to enter a car that is known to be 'ineligible'.
The Faenza-based outfit has now been asked to explain itself.