Some 300 prominent Canadians have sent a letter Canada's prime minister urging him to take action to get Al-Jazeera English journalist Mohamed Fahmy freed from an Egyptian prison and returned to Canada.

Former Canadian Prime Minister Paul Martin, Supreme Court of Canada justice Louise Arbour and author Michael Ondaatje are among those who signed the letter to Prime Minister Stephen Harper.

Fahmy, a Canadian, and two other journalists were sentenced to three years in prison this month in for airing what it described as "false news" and biased coverage, a case long criticized by press freedom advocates.

Authorities arrested the journalists and charged them with allegedly being part of the Muslim Brotherhood and airing falsified footage intended to damage national security.

The journalists say they were simply reporting the news.