Ottawa's top cop is asking residents to maintain their trust in the city's police force while an investigation continues into an alleged assault of a taxi driver by an off-duty police officer.

"I guarantee to you if our officers didn't handle it appropriately they will be held accountable," Chief Vern White told CTV Ottawa on Thursday.

Faith in the force has been strained since an investigation was launched into an alleged assault of the taxi driver by an off-duty police constable at the Ottawa International Airport earlier this week.

Taxi driver Sami Aldoboni, 43, says the assault happened after a vehicle, a grey Nissan Xterra SUV, tried to pass his taxi unsuccessfully on Ottawa's single-lane Airport Parkway on Monday.

After that, Aldoboni says the driver followed his cab -- tailgating him for nine kilometres -- to the taxi holding area at Ottawa's International Airport where the beating took place. Aldoboni is now recovering from two broken bones in his left arm and a broken finger.

"My frustration is people are pre-judging everything that happened and whether we are doing the right thing," said White.

The province's Special Investigations Unit, which is brought in whenever police are involved in incidents that result in serious injury or death, is now investigating the case.

Ottawa police will also investigate how uniformed officers dealt with their colleague when they arrived on scene.

Still, taxi drivers who witnessed the attack say there's a double standard and the taxi union is calling for the officer in question to be suspended.

White has already met with taxi union leaders to deal with those concerns.

Despite criticism from the taxi union, a communications expert from Carleton University says police are doing their best to be transparent at a crucial time because they need the public, and especially taxi drivers, to trust them.

"They know that cab drivers can be extra eyes and ears. There are more cab drivers roaming the streets day and night than there are patrol cars," said Jeff Sallot.

In the meantime, the four SIU investigators assigned to the case will be given access to footage captured by airport security cameras, as well as the security camera in Aldoboni's taxi.

While the investigation continues, the constable in question will remain on-duty. However, he's been re-assigned to a desk job.

If the investigation results in charges, it will be the fourth time criminal charges have been laid against an Ottawa police officer in one year.

With a report from CTV Ottawa's Kate Eggins