The parents of an imprisoned Egyptian-Canadian journalist arrived in Cairo Thursday as local prosecutors interrogated their son on suspicions of broadcasting false news that harmed national security.

Mohamed Fahmy's family insisted there was no truth to the allegations against the 40-year-old, who is spending his third week languishing in a cold, dark, insect-ridden cell at an infamous

"The accusation about him fabricating news... I'm pretty sure that this accusation is not about Mohamed," Fahmy's younger brother, Sherif, told The Canadian Press in an interview from Kuwait.

Fahmy along with Australian correspondent Peter Greste and Egyptian producer Baher Mohamed were working for satellite news broadcaster Al-Jazeera English when they were arrested Dec. 29.

Authorities apprehended them in a Cairo hotel room where they had been working after the Egyptian government raided the offices of the Qatar-based satellite news broadcaster.

None have been officially charged but Egypt's Interior Ministry had said the arrests were part of a crackdown on the Muslim Brotherhood, which the military-led government branded a terrorist organization after overthrowing former Islamist President Mohammed Morsi in a coup in July.

In a new development Thursday, Egypt's chief prosecutor's office said in a statement that some of the detained journalists confessed to being members of the Muslim Brotherhood, without specifying who.

Fahmy's brother said reports he had seen about the statement were confusing as Fahmy's lawyer, who was present at Thursday's interrogation, told him allegations of ties to the Brotherhood hadn't come up.

"None of his hearings have anything to do with this at all," Fahmy's brother said. "This is not related to Mohamed."

Hoping for intervention

Al-Jazeera also rejected the Egyptian prosecutor's claim against its three detained journalists, saying the statement was "unusual."

"It looks like a pre-judgement on an ongoing investigation," a spokesman for the network said. "Claims that anyone has 'confessed' are rejected by our journalists and legal team."

Fahmy's next interrogation is set for next week, his brother said.

The family is now hoping Fahmy's parents, who flew to Cairo from Montreal, will be allowed to see their son.

"We're pushing hard for them to be able to see Mohamed within the next couple of days — he requested that, so we're hoping it will happen soon," Fahmy's brother said, adding that an older sibling, Adil, was also travelling to Cairo on Friday.

There are also hopes that a letter sent days ago by Canadian officials asking Fahmy to receive attention at a hospital for an injured shoulder will be heeded by Egyptian authorities, his brother said.

As the journalist's detention in Cairo appears set to continue, Fahmy's family is hoping Canada will be able to secure his release with diplomatic pressure similar to what was seen when two other Canadians — John Greyson and Tarek Loubani — were detained in Egypt last year.

"All our hopes is that the Canadians will intervene," said Fahmy's brother, who has voiced concerns that Ottawa isn't doing enough on the case. "We're hoping that this is going to lead to his release."

A government official speaking on the condition they not be named said Canadian officials had been in regular contact with Fahmy's lawyer and Fahmy's other brother, Adil.

'Dedicated journalist'

Fahmy hasn't been allowed many visitors but Nancy Youssef, a friend and fellow journalist in Cairo, managed to speak briefly to him while he was in a holding cell at a different detention centre awaiting interrogation last week.

"I don't think he knew what day it was, what time it was," she said in a phone interview. "He told us 'I'm being held the worst of anyone.'"

The entire situation has been alarming for Youssef and her fellow reporters.

"We all know him and have never known him to be anything but a consummate professional and a dedicated journalist," she said. "He has only advocated for telling the story."

The recent arrests have deepened the uncertainly around reporting practices in the country, she said.

"We're not advocates of anybody's cause, we're here to report on what's happening at a very important time in Egypt," said Youssef. "The challenge is you never know when the rules change."

Fahmy has been interrogated four times so far — Canadian officials weren't present for the first instance, his brother said, adding however that Fahmy continues to hope Ottawa will do something to secure his freedom.

"Yesterday his fiancee was able to meet with him for a couple of minutes," Sherif Fahmy said. "Last thing he said was 'I have full faith that the Canadians will get me out of this."'

Fahmy's family moved to Canada in 1991 and his parents still live in Montreal. He finished school in the city and then went on to graduate from a university in Calgary.

As a journalist he covered stories for the New York Times and CNN among other news outlets before moving to Egypt in 2011 and eventually becoming Al-Jazeera's bureau chief in Cairo.

More than 50 news organizations from around the world denounced the arrests and called on Egyptian authorities to release the three journalists and to stop arbitrary detentions of media representatives.

Egypt's top prosecutor has said the journalists would be held through the end of the month for interrogation.

With files from The Associated Press