Supporters of five Muslim men held in Canadian prisons without charge, on secret evidence, want the prisoners released and Canada's security certificate process abolished.

The families and friends of the suspected terrorists marched to the Prime Minister's Office in Ottawa Monday to press their demand for the abolition of the security measure under which the men are being detained.

Canada's security certificate system allows police to arrest and imprison anyone deemed a threat to national security, without charge or bail. Under the system any evidence against the suspected terrorist is withheld from family, friends and even lawyers.

Mona Elfouli's husband Mahammad Mahjoub has been in detention since 2001.

"I'm asking Mr. Prime Minister please, we're not asking for more than a fair trial. Show the evidence, allow the lawyers to defend their clients," Elfouli told reporters in Ottawa.

Mahjoub and four others are being held without charge, or bail, because of suspected ties to terrorist organizations.

Mohamed Harkat was taken into custody in Ottawa last November. He is accused of having ties to a sleeper cell of al Qaeda, but his wife Sophie says if he was a terrorist she'd know it.

"I've been fighting the government for 10 months, but nobody seems to be listening," she says.

Ahmad Jaballah's father, Mahmoud, has been behind bars in a Toronto detention centre since August, 2001.

"It's something against Muslims these days going all around cities. It's not just against my Dad," Jaballah said.

The 17-year-old believes the prolonged detention is an example of racism. In the hopes of piquing the government's attention he presented the PMO with a petition his father and the others be released.

"It says either show the evidence or release them and end the secret trial," Jaballah said as he handed the petition over. "Can you show the Prime Minister? That would be appreciated."

The petition was accepted, but the group was refused an official audience with the PMO. Still, it's the closest they've come to getting the government to listen.