The lawyer for a Canadian who has been imprisoned for more than five years in the United States for allegedly assisting al-Qaeda fears a deal to have him released may fall through because of a lack of support from Ottawa.

Mohammed Abdullah Warsame, a 35-year-old born in Somalia, was charged in 2004 with five counts of supporting terrorism.

The 5½ years he has spent in custody is the longest time anyone in the continental United States has waited for a trial in over 200 years, said Warsame's lawyer, Peter Erlinder. Four of those years were spent in solitary confinement.

Last month, U.S. federal prosecutors offered to drop the five charges of material terrorism if Warsame pleaded guilty to a lesser charge of conspiracy to support al-Qaeda.

Under the plea agreement, Warsame admits to conspiring with others to provide al-Qaeda with personnel, training and currency starting in March 2000.

He also admits to having attended several al-Qaeda training camps in Afghanistan, including one where authorities said he met al-Qaeda leader Osama bin Laden.

Warsame is due to appear in U.S. Federal Court on July 9 for sentencing. It's not immediately clear whether he would be released or have to serve additional time.

'No assurances'

The plea is contingent on Warsame returning to Canada. Erlinder told CBC News that he has received no indication from the Harper government that it will issue the documents Warsame needs.

"We have no assurances from either the U.S government or the Canadian government that Canadian law will be followed in Mr. Warsame's case," Erlinder said.

"Due to the Privacy Act, I cannot comment on the specifics of the case," said Alain Caccione, spokesman for the Department of Foreign Affairs and International Trade. But he added that "any Canadian citizen has the right to return to Canada."

Canadian officials have paid Warsame regular visits, Caccione said.

Erlinder disputes this assertion.

"Let me just say they have not been active in his case at any time," Erlinder said.

Erlinder says his client may face the same fate as Omar Khadr and Abousfian Abdelrazik, two other Canadian citizens accused of terrorism who have been detained abroad.

The federal government has refused to repatriate either man, drawing criticism from MPs and human rights groups.

History with al-Qaeda

The charges against Warsame related back to his activities beginning in 2000, when he left his Toronto home for Afghanistan to attend al-Qaeda training camps.

"Like many young Muslims, he was attracted by the notion of an Islamic state he believed was a sort of utopia," Erlinder said.

But Warsame soon grew disillusioned with al-Qaeda, he said.

Warsame returned to Canada in March 2001, then relocated to Minneapolis, where he attended a technical college. Throughout 2002 and 2003, he exchanged emails and provided information to several people associated with al-Qaeda, according to documents that outline the plea agreement.

The Federal Bureau of Investigation arrested him in 2003 after seeing him at a Minneapolis mosque talking to Zakarias Moussaoui, known later as the 20th Sept. 11, 2001, hijacker.

Erlinder claims the FBI wanted Warsame to lie and say Moussaoui had admitted to him that he was the 20th hijacker. When Warsame refused, authorities charged him with supporting terrorism, Erlinder says.

With files from Bill Gillespie