As the officer arrived at the driver's side of the vehicle it was driven forward, so he had reached through the window to try to turn the engine off.
The driver had then grabbed the officer's wrist and accelerated forward at the same time, leaving the officer unable to free himself.
As the vehicle had gained speed, the officer was able to put his other arm through the open rear window and hold on to the vehicle's pillar.
After being thrown from the car, the injured officer was helped by a colleague and members of the public. Inspector Mastrovich expressed his gratitude to the people who helped.
The officer's legs and arms were grazed. The vehicle fled the scene, but police inquiries resulted in the arrest of a 26-year-old Wanganui man on Monday.
He has been charged with dangerous driving causing injury, failing to stop for police and driving while suspended, and will appear in the Whanganui District Court on Tuesday.
Police said further charges were likely.