Daniel Maldini, the son of Italy and AC Milan legend Paolo Maldini, tested positive for alcohol and an initial drugs screening after a road accident involving six injured people.
The incident happened after a Cagliari match. Further details have now emerged following the crash, which had already been reported.
According to Sport Mediaset, Maldini underwent alcohol and drugs testing in hospital after the accident.
Both breathalyser tests returned positive results, recording 0.91 and 0.89 mg/l of alcohol in his breath.
A preliminary test for drug use was also positive. The result of a toxicological analysis is now awaited.
Maldini could face serious problems as a result of the accident.