The crash took place shortly after midnight on the Autobahn 44 near Dortmund while the police officers were waiting to intercept a suspect vehicle.
The car was badly damaged by the impact and subsequently caught fire.
The officers, a 46-year-old policewoman and her 51-year-old male colleague, were unable to get out of the vehicle and died at the scene of the accident.
The 34-year-old truck driver was found to be under the influence of drugs. Blood samples have been taken for further testing.
The Autobahn 44 in the direction of Dortmund was completely blocked in the hours afterwards.