Sami Aldoboni, an Ottawa cab driver, said his arm was broken by a man who identified himself as an off-duty police officer. (CBC)

An Ottawa police officer is under investigation after a cab driver said he was assaulted in the aftermath of a road rage incident at the Ottawa airport, police confirmed Wednesday.

Sami Aldoboni said he was driving his taxi on the Airport Parkway on Monday afternoon when a sports utility vehicle suddenly came up behind him, tailgating him all the way to the airport.

He said when he pulled into the taxi parking area, the driver of the SUV pulled up behind him.

"He just immediately started shouting and swearing and using some obscene language. When he grabbed me and pulled me to the ground and he jumped on me … that's probably where I broke my finger," said Aldoboni, whose arm was also broken during the altercation.

When other cab drivers tried to step in to help Aldoboni, the other man identified himself as an off-duty police officer.

"With a big smile on his face, he showed me the police identification card," said Mohammad Atiya. Several other police officers arrived soon after.

"They were just basically pushing everybody aside and protecting him when he's the one who just finished hurting our driver," said Amarber Sohi.

Steve Boucher of the Police Association said the officer was also injured.

"I know this officer quite well and I know this officer to be of very good moral character and a very good person," he said.

Alidoboni, who was still on painkillers two days later, said he can't believe a police officer would exhibit such behaviour.

"From the depth of my heart, I really wish that he was not a police officer because this is a shame," he said.

The provincial Special Investigations Unit, which probes incidents involving the police and civilians that have resulted in a serious injury or death, has been called in to investigate the case.