Officers were responding to an emergency in the Openshaw area around 11:50 p.m. Sunday evening (August 8) when it collided with the taxi.
A 45-year-old man was taken to hospital with serious injuries where he remains in stable condition.
Read more:Serious incident closes the road with CSI police officers at the scene
It is not clear whether this was the taxi driver or a passenger.
A policeman was also taken to hospital with minor injuries as a result of the crash, GMP said.
He has since been fired.
Alan Turing Way at the Ashton Old Road junction was taped for several hours as emergency services responded to the incident.
Police, firefighters and the ambulance service all attended the scene.
A police van was seen lying on its side, across the median of the road.
Further down the road, at the crosswalk, a white car was positioned so that its rear and bumper faced the sidewalks on either side of the road.
Debris could be seen strewn on the road and the front of the white vehicle was badly damaged.
The accident was referred to the Police Professional Standards Directorate “in accordance with normal procedure,” police confirmed.
A spokesperson for GMP said: “Shortly after 11:50 pm last night (Sunday August 8, 2021), a police car was responding to an emergency incident when it collided with a taxi at the Alan Turing Junction. Way and Ashton Old Road.
“Emergency services responded and a 45-year-old man was taken to hospital with serious injuries where he remains in stable condition.
“An officer suffered minor injuries which were treated in hospital. He has since been released.
“An emergency patrol attended the initial emergency incident and the collision was reported to the Professional Standards Branch in accordance with normal procedure. “