A team, accompanied by police and firefighters, were seen using a small digger to lift the police car from its position at about 15:00.
A spokesperson for Hampshire Police revealed the officers in the car had been carrying out urgent inquiries in relation to an indecent assault in Wallace Court, Newport.
A 29-year-old man from Ryde has been arrested.
The Island Line Train runs along the pier between Ryde Pier Head station and Ryde Esplanade, there is also a walkway and a lane for vehicles.