The family of a Canadian man beheaded by a fellow passenger on a bus have spoken of a little guy with a big heart.

Tim McLean, 22, was returning home to Winnipeg from a job as a carnival worker in Edmonton when he was killed by a man who stabbed him 50 times and then cut off his head with a huge knife.

A policeman reported seeing the attacker hacking off pieces of the victim and eating them, according to a tape leaked on the internet.

Newspaper deliveryman Vince Weiguang Li, 40, of Edmonton is charged with second-degree murder.

The victim's uncle, Alex McLean, reading a statement from the family, said: "He was a little guy with a heart bigger than you could know.

"Tim spent his life travelling and meeting new people, and always saw the good in everyone. He had the most infectious giggle.

"You could hear him laughing a mile away. It didn't matter what kind of a day you were having because, when you heard him laugh, you couldn't help but join in."

In the tape of police radio transmissions, a Royal Canadian Mounted police officer referred to the attacker as "Badger" and said he was armed with a knife and a pair of scissors, and "is defiling the body at the front of the bus".

"Okay, Badger's at the back of the bus, hacking off pieces and eating it," he said at the end of the recording.

Police responded to a call to a desolate stretch of the TransCanada Highway about 20km from Portage La Prairie, Manitoba, after the bloody killing on the Greyhound bus travelling from Edmonton to Winnipeg.

Friends have started a Facebook group to remember him.

Passengers said that soon after they re-boarded the bus after a break, the suspect - for no apparent reason - stabbed Mr McLean dozens of times as others fled in horror.

He then severed Mr McLean's head, displayed it and began hacking at the body.

Mr Li's boss was shocked to learn his "model employee" was the accused. "He was a very nice, polite guy," said Vincent Augert, who distributes newspapers in Edmonton.

"He was very punctual and always cleanly dressed."

In court in Portage la Prairie, Mr Li did not reply when the judge asked him whether he was going to get a lawyer, and nodded only slightly when asked whether he was exercising his right not to speak.

The prosecutor asked for a psychiatric assessment, but the judge said Mr Li should have a chance to meet his lawyer.