CBC News has obtained video of another violent takedown by private undercover security guards, this time at Vancouver’s Pacific Centre Mall.

The shaky cellphone video shows a man who appears to have one leg, in an electric wheelchair, surrounded by three undercover security guards who suspect him of shoplifting.

One of the guards starts swearing, before knocking the man out of his wheelchair with a blow to the head.

"I'll f--kin' throw you on the ground and f--k you up!" the guard is heard saying on the video. "Don't f--k with me ... On the ground! On the ground! On the ground! You're so stupid — on your chest!"

One eyewitness who doesn’t want her name used because she works nearby sent the video to CBC News. She said the incident was witnessed by up to 50 people, many of whom demanded the guards stop and called police.

Doug King of the Pivot Legal Society says even if the suspect was physically resisting arrest, nothing justifies the violent takedown.

"I wouldn’t even call that an arrest — I’d call that an assault," he said. "There’s nothing in the law that authorizes you to strike somebody like that."

King says it’s unlikely the guards seen in the video were doing what they were trained to do.

"The language really stands out — it proves that this wasn’t even an arrest, it was an act of violence," he said.

"It’s an example of when security guards get a little too emotional in situations — just because someone commits a criminal offence, it doesn’t mean they don’t have any rights, and they have the right not to be assaulted by people."

The B.C. Ministry of Justice has launched an investigation, Minister Shirley Bond said in a statement late Wednesday.

"I have seen the video and I find it very troubling," Bond said. "The investigation will determine if there was any inappropriate action on the part of these security workers."

Bond said there is a range of sanctions available to the registrar of the Security Services Act, "from warnings and violation tickets to license suspension or cancellation."

Guards acted accordingly, says employer

The guards are employees of the Genesis Security Group, which is under contract by the Downtown Vancouver Business Improvement Association to patrol member businesses, including those in Pacific Centre Mall.

Genesis Security Group vice-president Ashley Meehan says man in the wheelchair resisted arrest and the guards responded to the situation accordingly. (CBC)

Genesis Security vice-president Ashley Meehan says the company is investigating and takes the incident very seriously.

"When we look at footage like that, obviously we need to look at the whole situation," he said. "We’re looking at about a 30-second video of something that would have been several minutes long as an incident."

Meehan says the victim has multiple prior cases of shoplifting and theft.

"He was identified in breaking the law, with shoplifting, and was approached on this and did resist and the guards themselves responded to it accordingly and obviously have to make the arrest," Meehan said.

"As far as I know he was being aggressive towards them … and there was possible assault."

Karen English with the Justice Institute of B.C., which created the curriculum for licensing security workers in the province, says it’s up to the guards themselves to ensure they work within the parameters of the law.

"I think the individual’s responsibility begins before the training," she said.

"The responsibility of the employer, the hiring process, the training is one thing — going beyond that is the individual and other things that may affect how they perform their actions."

Both the Downtown Vancouver Business Improvement Association and Cadillac Fairview, the company that owns Pacific Centre Mall, say they are also investigating the incident.

According to the Vancouver Police Department, no charges were laid against the guards or the alleged shoplifter.

The incident comes a week after CBC News broke the story of a teenager who was pushed to the ground and arrested by security guards at Burnaby's Metrotown Mall.