Two police officers involved in the one-vehicle crash, which left part of the motorway closed this morning, have been taken to hospital for brain and back injuries.
The officers were responding to reports of a drunk driver, according to head of Road Policing Unit Chief Superintendent Stewart Carle.
The crash, involving one vehicle, occurred shortly before 10pm on Sunday night on the northbound carriageway of the M90 Edinburgh to Perth motorway about 1.5 miles north of Junction 4 (Kelty).
At about 11.30pm, Fife police put out a warning to motorists to avoid the area.
The stretch between junctions four and five was closed off this morning for investigation, however all lanes have now been cleared.
Police Scotland said emergency services attended at the scene, where the driver was removed from the vehicle by Fire and Rescue Service personnel.
He was later taken to Edinburgh Royal Infirmary, then transferred to Western General Hospital in Edinburgh with neurological injuries.
The passenger was taken to Ninewells Hospital with back injuries.
Chief Inspector Mark Patterson from Road Policing East said: “The officers in the patrol car were responding to the report of a drunk driver on the motorway when the collision happened.
"Our thoughts are with both officers and their families at this time.
"I would appeal to anyone who may have witnessed this collision to call Police Scotland on the 101 number quoting the incident reference number 3798 6/10.”