The United Nations terrorist list, which includes a Canadian who the government won't let back into the country, is not 100 per cent reliable, a UN official says.

"I think there are names on there that shouldn’t' be there," said Richard Barrett, who co-ordinates the list and is conducting a review of it. "I think there are names there without enough identifying particulars."

One of the 370 individuals on the list is Abousfian Abdelrazik, a Montreal man stranded in Sudan for six years as an al-Qaeda suspect.

Both the RCMP and Canadian Security Intelligence Service have cleared Abdelrazik, a Canadian, of any terrorist connections, but the Conservative government refuses to issue him travel documents to return home because his name was added to the UN Security Council list banning travel for terrorist suspects.

Barrett said the UN committee that is studying all 370 names on the list will need a year to complete its work. He said Abdelrazik's file has already been reviewed but would not say at this point whether his name will remain or be taken off.

On Thursday, Federal Court Judge Russell Zinn denounced the UN terrorist list as a "violation of natural justice" and ordered the Harper government to immediately issue Abdelrazik an emergency passport and to fly him back to Canada within 30 days.

Zinn described the process the UN uses to put individuals on the list as "frightening."

A committee of the UN Security Council meets in secret to make decisions about the list using information that comes from national intelligence agencies.

The accused individual has no right to know the allegations against them or which country asked to have them listed.

Barrett said that once a person gets on the list, it's virtually impossible to get off.

"I think there are names on there we all believe to be dead," he said.

For example Omar Khadr's father, Ahmed Said Khadr, who was killed five years ago by the Pakistani military, is still on the list.

But despite possible problems, Barrett defended the list, saying it is a useful tool that allows courts to seize alleged terrorists' assets, stops them from flying and prevents anyone from giving terrorists money.