Lindsay Lohan has been treated in hospital after crashing into a truck in a Porsche.

The car was completely written off and barely recognisable from the front as the roof completely caved in on top of the windscreen, but the troubled actress remained unharmed.

The Mean Girls actress spend two hours undergoing tests following the accident in which the car she was reportedly driving smashed into a 18-wheel big rig on the Pacific Coast Highway, west of Los Angeles.

According to The Hollywood Reporter, a Santa Monica Police Department statement said that police "responded to a traffic collision involving a large dump truck and a black Porsche occupied by Lindsay Lohan and an adult male".

"A preliminary investigation revealed that both vehicles were driving northbound on Pacific Coast Highway when the Porsche struck the rear end of the dump truck. Cause of the accident is under investigation."

The statement continued: "The occupants of the black Porsche were determined to not be impaired and were [taken] to a local hospital for treatment of minor injuries,

"Investigators are attempting to determine the driver of the black Porsche at the time of the collision."

A publicist for Lohan said the actress was on her way to a movie set when the crash occurred, and she was taken to a hospital "as a precaution", but was released in less than two hours and was "fine".