Montreal A Montreal teacher has been suspended for showing high-school students a video that police believe shows the slaying and dismembering of a Chinese student, authorities said Wednesday.

Police suspect Luka Magnotta of killing Jun Lin and posting a video online that shows him stabbing and having sex with the dismembered corpse. The case drew national attention when Lin's body parts were mailed to the headquarters of two of Canada's main political parties, and provoked an international manhunt when Magnotta fled to Europe. Magnotta was caught Berlin last week and is facing extradition.

Montreal police said Wednesday that DNA results confirmed that two body parts mailed to two Vancouver schools last week belong to Lin. His head is still missing. The teacher was suspended with pay on June 4, the same day he showed the video.

The school board released a statement calling the teacher's behaviour inappropriate and offensive. Staff at Cavelier-De LaSalle High School said that a team of psychologists was available to deal with any problems. The teacher's name was not released.

The video is so disturbing that, according to Montreal police, even seasoned detectives who watched it were troubled.

The teacher, whom one student described as being in his 20s, had been under contract to teach a 10th-grade history and citizenship education class through the end of the year.

Education Minister Michelle Courchesne criticised the teacher.

“It’s horrifying,” Courchesne told reporters in Quebec City. “It’s a very, very serious and total lack of judgment. I don’t see any educational value in that.”

Some students defended the teacher.

Maude Aubin-Boivin, 17, who was in the class when the video was played, said it was it was the kids who asked the teacher to show it. She said the teacher hesitated and that a few of her classmates objected. In the end, the class voted with a show of hands 22 to 3 in favour of watching it, she said. The three who voted against it stayed and watched anyway.

“He's a very good teacher,” Aubin-Boivin, 17, said. “Honestly, his courses are super fun. He's a teacher who knows his job and who knows how to teach.”

Before showing the video, she said, the teacher warned the class, “‘Watch out, for sure there are images that could be shocking.’” She said he fast-forwarded through some of the video.

Aubin-Boivin said the contents were troubling, but insisted she was fine. “For sure, at the beginning I found it tough,” she said. “But I wasn't traumatised or anything. We see so much these days on TV.”