Tarek Loubani of London, Ont., and John Greyson of Toronto were detained in Cairo on Aug. 16. They have yet to face formal charges.
On Sunday, Justin Podur, a friend of the Canadians held in Egypt, told CBC News that "their detention has been extended…for 15 days."
Podur said he intended to issue a media release on the situation later Sunday afternoon.
Loubani, a doctor, and Greyson, a filmmaker and university professor, had been intending to make their way to Gaza.
Foreign Affairs officials have said they believe Loubani and Greyson were simply in the wrong place at the wrong time when they were detained.
There was no immediate comment from Foreign Affairs on the news of the two men’s extended detention.