VANCOUVER -- A Vancouver police officer used excessive and unnecessary force when he punched a driver three times during a traffic stop in 2012, said a ruling by B.C.'s police watchdog.

In a decision released on Wednesday by the Office of the Police Complaint Commissioner, adjudicator Alan Filmer said Const. John Gibbons and another police officer approached a BMW that was stopped at a red light in June 2012, when they realized the car was associated with a prohibited driver.

Both officers walked up to the vehicle and ordered the driver, James Feng, to roll down the windows, said Filmer, but Feng appeared to ignore them. The man just stared ahead and picked up his cell phone, so Gibbons, thinking Feng might try to flee, smashed out the passenger side window with his baton and entered the car.

Gibbons then punched Feng in the head three times, Filmer said.

"The first blow was significant, as the officer broke his hand. Const. Gibbons testified that the second and third blows were less forceful because his hand was fractured. The force of the blow split Mr. Feng's scalp in a 3 centimetre cut."

The ruling said the officers then arrested and searched Feng, and they determined he was carrying false identity papers and was prohibited from driving.

Filmer said while the two officers had reasonable grounds to make a traffic stop and arrest and search Feng, there was no need for Gibbons to beat the man, particularly when traffic at the time was so congested that it was unlikely Feng could get away.

Gibbons also knew where Feng lived based on the registered address attached to the car, he said.

"Constable Gibbons could have attempted to communicate verbally with Mr. Feng," Filmer wrote. "First, it was important to determine whether Mr. Feng spoke English and was able to comprehend the commands of the officers. Second, it was important to determine whether Mr. Feng was incapacitated because of fear, and was now willing to obey the commands from the officer."

Filmer said Gibbons could also have tried to take the vehicle out of gear or turn the car off to stop the driver from fleeing.

Gibbons' partner that night originally faced allegations of using excessive force and recklessly searching Feng's car without sufficient cause as well, but those allegations were dismissed.

The commission must now determine if any disciplinary action will be taken against Gibbons and it has asked lawyers to make submissions by Aug. 25.