When Mike Tyson, the heavyweight champion, crashed his $180,000 silver Bentley convertible into a parked car in lower Manhattan Sunday, two Port Authority police officers offered to help. And Tyson offered them the car, saying, ''I've had nothing but bad luck and accidents with this car.''

According to Lynn Tierney, a spokeswoman for the Port Authority, the officers, whom she declined to identify, at first refused Tyson's offer of the Bentley. But when he insisted, they accepted the car and put it in a private garage in Jersey City. By doing so, Tierney said, the officers violated regulations concerning the acceptance of gratuities.

''The next day, the commanding officer at the Holland Tunnel command ordered the officers to return the car,'' Tierney said. ''At which point they did it. The company the car was registered to, C.J.T. Inc. -Tyson's a principal of that - was contacted, and they sent somebody down to pick the car up.

Tierney said that the Manhattan District Attorney's office had reviewed the case and declined to prosecute, and that the Port Authority was reviewing the case to see if there had been any administrative infractions.