In a dramatic video played to the court, the officers drag the 19-year-old passenger out of the car and put him face down on the asphalt before they cuff his hands behind his back.

No charges were ever laid against either the driver of the car or the passenger following the traffic stop late on Australia Day last year.

But Senior Constable Matthew McVicar, 35, and Constable James Head, 29, were later charged with assault occasioning actual bodily harm following the altercation. They have pleaded not guilty, and their lawyers said at the outset of a hearing on Tuesday that the officers were acting in the execution of their duties.

It was about 10pm on January 26 last year. The driver had just picked up his friend and his friend's girlfriend from an Australia Day party in Belconnen. The alleged victim said he had been drinking that day, about 10 to 15 beers since midday, but denied he was being aggressive.

The driver told the ACT Magistrates Court at the hearing on Tuesday that he was unfamiliar with Civic streets, and on the way home accidentally drove straight through the bus interchange on East Row towards London Circuit, where cars are not allowed to go.

The two general duties police officers saw the car and turned on their lights. The driver told the court he could not see anywhere suitable where he could immediately pull over, so he had used his arm to indicate to police out the window that he would turn into the car park opposite Mooseheads, about 50 to 100 metres away.

Once pulled over, prosecutors say Snr Constable McVicar had a short conversation with the driver before both officers left to talk to another person walking past.

The next conversation with the police officers is filmed by the front seat passenger, who is the alleged victim's girlfriend. She told the court she had started filming because the officers were acting "strange" and "aggressive".

A Canberra Times request to the court registry for access to the footage went unanswered.

The video shows Constable Head walk up to the car and demand to see the driver's licence. The back seat passenger is heard to comment, "please".

"What is your problem, do you not know how to drive?" Constable Head asks the driver.

"I do sir, sorry," the driver replies.

"So what happens when a police officer puts his lights on behind you?" Constable Head says.

The back seat passenger tries to answer the question, before he is warned that if "you don't shut your mouth I'll pull you out and arrest you for hinder".

The officer tells the passenger to produce his driver's licence, but he replies that he does not have his wallet.

"Alright get out of the car, I'll be searching you for being a smart arse," Constable Head says, "Get the f--k out of the car now."

It's alleged one officer had the teenager in a headlock and the other had his arm as they pulled him from the car.

The teenager, whose mother works for the Australian Federal Police, says to the officers that "you are abusing your power" and that they don't have the right to arrest him.

But the officers dispute the prosecution account of their first interaction with the group.

Snr Constable McVicar said that in the first conversation, the teenager had constantly interrupted him while he was trying to speak to the driver.

He said he warned the 19-year-old multiple times that he was hindering police and he would be arrested if he continued.

The officers also say that once they decided to arrest the teenager during the second, filmed, conversation, that he flailed his arms and legs to make it difficult to get him out of the car.

In cross-examination, Constable Head said his years in the army meant he often assumed the worst case scenario. He said his anxiety was heightened when the car didn't immediately pull over. He said he wished he'd chosen his words better, but believed he was acting within his duties to arrest the teenager for hindering police.

In response to questions about why he did not tell the teenager why he was being arrested, the officer said police only had to tell someone why they were under arrest "when most convenient".

"There's no power in police to arrest someone for being a smart arse is there?" prosecutor Dean Sahu Khan asked Snr Constable McVicar in his cross-examination. "No, your Honour, there is not," he responds.

The two officers are suspended from work pending the outcome of the hearing, the court heard.

It was standing room only on the first day of the hearing, which is expected to go for a second day on Wednesday before Magistrate Robert Cook.