Paul Derksen, 50, a City of Edmonton traffic officer, was charged with kidnapping and sexual assault in 2017. (Supplied)

EDMONTON -- The peace officer accused of sexually assaulting a woman after pulling her over while off duty pleaded not guilty Monday.

On June 4, 2017, Edmonton police said Paul Derksen, in uniform and in his personal vehicle, pulled over a woman in the area of 91 Street and Anthony Henday Drive at approximately 2 a.m.

The victim, whose identity is protected under a publication ban, told court Derksen said she was swerving, asked her to get out of her car and into the front seat of his, and took her phone and keys.

“Getting inside I didn’t notice any type of computers or radios, scanners—something I thought a typical police vehicle would have," she testified.

The woman, who had been celebrating a cousin's birthday and drank four beers, said the peace officer told her she could be charged with a DUI and offered to drive her home.

"While we were driving, he put his right hand on my left leg and I instantly just felt panic because I knew that that was wrong," she said.

The woman then said Derksen asked her for a favour in return, parked at the Northlands parking lot, and "instructed" her perform oral sex on him, which she did.

Derksen, now 53 and facing kidnapping and sexual assault charges, told a different story.

He said he saw the woman swerving and could smell alcohol. He said he advised her to call someone for a ride and offered to call a taxi. He claims she said no one would give her a ride and that she had no money, so he offered to give her a ride and she accepted. Derksen testified the two did go into the parking lot, but it was because the woman was getting sick.

“I reached across to open the door and she grabbed me with both hands and she kissed me. And that's how it all started," Derksen testified.

He said he went with it at first, but then put a stop to it and drove her home.

Derksen's lawyer, James Rowarth, said the accused has been consistent with his story, and "it may be unusual, bizarre, but that doesn’t mean it's not true."

Back when police arrested Derksen, they said video the woman had shot inside the car was a "critical piece of evidence."

After court, the victim said "it was extremely difficult, especially to have that perpetrator in the room."

Derksen was working with the City of Edmonton Traffic Safety Section as an automated enforcement supervisor, but is suspended until the case and trial were concluded.

With files from CTV News Edmonton's Dan Grummett