File illustration photo shows a highway in Canada. A Chinese immigrant who beheaded and cannibalized a Canadian bus passenger in front of horrified travelers four years ago spoke out for the first time, saying he believed his victim was an alien

A Chinese immigrant who beheaded and cannibalized a Canadian bus passenger in front of horrified travelers four years ago spoke out for the first time, saying he believed his victim was an alien.

Vince Weiguang Li, 43, after being diagnosed with paranoid schizophrenia, was found not guilty of murdering 22-year-old Tim McLean on a Canadian Greyhound bus on July 30, 2008.

He has been holed up since his trial at a Winnipeg, Manitoba area mental health centre, where he has received treatment and is now eligible for escorted day trips into the community.

In an interview with Chris Summerville, head of the Schizophrenia Society of Canada, Li said he started hearing in 2004 what he believed was "the voice of God."

"The voice told me that I was the third story of the Bible, that I was like the second coming of Jesus (and that) I was to save people from a space alien attack," he said, according to a transcript published by Canadian media.

Li said he had purchased the knife used in the attack for protection "from the aliens" and claimed that he was unaware at that time that he suffered from schizophrenia.

"I was really scared. I remember cutting off his head. I believed he was an alien. The voices told me to kill him, that he would kill me or others. I do not believe this now," Li said.

Li had repeatedly stabbed McLean, who had been asleep on the seat next to him, cut off his head, removed his internal organs, pocketed his nose, tongue and an ear, and taunted police and bystanders with the severed head.

Police said in court documents Li "appeared to smell, and then eat parts of Tim McLean's flesh" and "lick blood from his hands" as they surrounded the bus on a desolate highway 90 kilometers (55 miles) west of Winnipeg, in western Canada, soon after the attack.

Authorities found body parts littered throughout the bus, some in white plastic bags. McLean's eyes and a third of his heart were also missing, and it is presumed Li ate them, said a pathologist in court files, though Li denied this.

The other 35 passengers and the driver were jolted by "blood-curdling screams" and fled, said witnesses, bracing the door after their escape to trap Li inside the bus. He was subdued by police after a three-hour standoff.

McLean, according to his family, was on his way home to Winnipeg from a job as a carnival worker in western Canada, when he was attacked.

Li, a devout Christian and a computer engineer, immigrated to Canada with his wife from China's province of Liaoning in 2001.