A British man jailed last year in the same Egyptian prison where two Canadians are being held says he found conditions "extremely difficult" in the overcrowded facility.
Alisdare Hickson of Canterbury, England spent 54 days at Tora prison, south of Cairo, after he was accused of throwing rocks, when he was only taking photographs during protests.
He said his cell housed between 70 and 85 people and was on permament lockdown 24 hours a day, seven days a week.
"My conditions were probably better than those for Egyptians, but still rather a nightmare," he told CBC News in an interview via Skype on Sunday.
London, Ont., emergency room physician Tarek Loubani and Toronto filmmaker John Greyson were taken to Tora prison after their arrest Aug. 16 in Cairo.
There are unconfirmed reports the two were arrested when they went to a police station to ask for directions to their hotel.
A lawyer representing the two men is due to meet with an Egyptian prosecutor on Thursday to try to get them released.
About 50,000 people have signed an online petition demanding the release of the Canadians.