A Montreal police officer already at the centre of an excessive force controversy has been caught on tape in another incident that is raising questions about her conduct.

The recent incident started with a man holding a beer on a public sidewalk and ended with four arrests and an accidental audio recording that captured the officer calling those involved "assholes" and describing how she nearly suffocated one man.

Police wouldn't identify the officer pending further investigation, but those involved say she gave her badge number, 728, a number which became infamous after a video posted to YouTube showed an officer with that badge number pepper-spraying seemingly peaceful protesters during a student march in the spring.

The video showing officer Stéfanie Trudeau, who wears badge 728, generated nearly 500,000 hits on YouTube. The officer was removed from protest duty pending an internal investigation.

The latest video, which captures an Oct. 2 incident in Montreal's Plateau neighbourhood, shows Trudeau and at least two other officers involved in a forceful confrontation, screaming and putting one man in a headlock.

The three men and one woman involved say the use of force was unprovoked and that they had no idea what was going on or why they were being detained.

They were eventually charged with obstruction of justice, assault and intimidation. All four deny that they were resisting the officers.

Started with open beer

Rudy Orchietti said he was holding open the door for one of his friends, who was loading audio equipment into a building that evening. Orchietti admits he had a beer in his hand.

He said Trudeau confronted him and asked to see his driver's licence and insurance.

Orchietti said he questioned why and alleges that he was then grabbed by the collar and thrown to the ground. He claims Trudeau pushed him, kneed him in the back and asked if he wanted to spend the night in jail.

His friend, Serge Lavoie, said he then tried to intervene, screaming for the officers to stop. A cellphone video shows officers followed Lavoie into a residence and dragged him out forcefully.

"[Trudeau] was on the way to strangle me," Lavoie said. "The further down we got, the more she was choking me and the more I was convinced she was going to kill me."

Conversation captured

After the incident, police seized the cellphones of the people involved. However, one was accidentally turned on, recording a conversation Trudeau had in a police car with her superior. The phones were later returned and the conversations were discovered.

"All the rats that were upstairs … these guitar playing [expletive] … all a bunch of red square types, all artists, basically a bunch of assholes, and they all started coming out of the apartment," Trudeau is heard saying on the recording.

Red squares refers to the symbols worn by supporters of the student protest.

At the station, still on tape, Trudeau implies that the four arrested were elevating the situation because they recognized her from the YouTube video from May.

Officer taken off patrol duty

Cmdr. Ian Lafrenière of the Montreal police said the force was only alerted to the cellphone recordings on Wednesday by a media report.

He said none of the four people involved made a complaint to the police service before speaking publicly.

"As soon as we learned [about it] we made the decision to take [Trudeau] off the street," he said.

"There will be a complete full investigation by internal affairs in this dossier and the investigators will be meeting different witnesses."