Supporters of a man who has been locked up for seven years in southern Ontario are taking his case to the United Nations.

Michael Mvogo has been in limbo since he was taken into custody in 2006 by the Canada Border Services Agency and held in immigration detention.

He had originally come to Canada in 2005, then been arrested by police for possession of a small amount of cocaine. After he pleaded guilty and served his one-day sentence, he was slated for deportation.

Immigration consultant Macdonald Scott mails a petition to a UN working group in support of his client, jailed immigration detainee Michael Mvogo. (CBC)

But officials said that he had entered Canada on a U.S. passport that wasn't his and that they couldn't determine his real identity.

He has spent much of the time since then in a provincial jail in Lindsay, Ont.

"It's been far too long and we demand that he be released," Macdonald Scott, Mvogo's immigration consultant, said Wednesday.

Scott and Mvogo's supporters filed a petition Wednesday to a working group of the United Nations High Commissioner for Human Rights, hoping for some kind of resolution from the international organization.

They say under international law, immigration detentions are supposed to be limited to 90 days, in most cases. But those rules are effectively voluntary.

In the U.S., detentions are limited to six months under a 2001 U.S. Supreme Court decision.

Canada has tried to deport Mvogo to the U.S., Guinea and Haiti, to no avail. Now, efforts are focusing on sending him to Cameroon, which he has more recently said is his home country.

'Keeping me here, it doesn't make sense,' Mvogo says of his continuing detention in a high-security jail in Lindsay, Ont. (Handout photo)

"I was ashamed to go back to my country with nothing in my pocket after so many years," Mvogo says in an audio recording from the Lindsay jail, explaining why he didn't disclose his real identity for so long.

"You know keeping me here, it doesn't make sense."

Audrey Macklin, a law professor at the University of Toronto and expert in immigration and human-rights matters, said Mvogo's case points to an issue with how detainees are treated under Canadian immigration law.

"As long as the Canadian government says it intends to deport them, they are effectively in limbo," Macklin said.

A big problem is that federal officials simply haven't been able to deport Mvogo because "they cannot obtain a travel document from Cameroon," his lawyer Jean-Marie Vecina said

Meanwhile, the cost of holding immigration detainees in high-security jails is steep, according to Mvogo's supporters. They say that at $239 a day, it has cost the government more than half a million dollars to keep him behind bars while it tries to deport him.