THE parents of a Brisbane journalist being held without charge in Egypt say they have already reached breaking point as they face the prospect their son could stand trial on terrorism related charges.

Peter Greste, who is normally based in Kenya but was relieving another journalist for three weeks in Cairo, and two other Al Jazeera English colleagues have been held in a maximum-security prison in since December 29.

The trio, who had been reporting on the political unrest in Egypt at the time, is accused of holding illegal meetings with members of the outlawed Muslim Brotherhood.

News from Egypt overnight suggests they will be among about 20 people to face trial accused of aiding members of a terrorist organisation.

Peter's parents, Juris and Loris Greste, who spoke in Brisbane today, say they have endured the most harrowing, stressful and difficult four weeks of their lives dealing with the situation.

Mr Greste said events were changing at lightning speed, each move affecting Peter's immediate future, and his comments could quickly become out of date.

"Someone didn't like their reporting and for that they are now put into a maximum security prison for what is clearly punishment, not mere detention," he said.

"This is most undeserved, outrageous and shameful.

"It's unbecoming of a great nation like Egypt, it's unbecoming of any civil society to behave like this.

"It's demeaning of any community which even pretends to be democratic and fair."

Mr Greste said while there were, of course, underlying complexities in this situation, he understood the Egyptian prosecutor-general had issued a press statement, which he had not read.

He said he understood, through that, that his son's case would be referred to court and further Al Jazeera journalists would be charged formally.

Mr Greste said the total number of people expected to be rounded up was likely to be 20 and he believed there was a serious risk that other Al Jazeera journalists or staff arriving in Egypt could be arrested.

"While I've read the report of allegations of airing false news there are still no specific charges," he said.

"One would reasonably suspect then that if this is the actual news … there would be more detail about what particular aspect of their wrongdoing is false.

"In any case the trial would have to be based on what was in fact broadcast, not on their script or notes or other records.

"We are absolutely confident that the broadcast material did not contain any falsity, inflammatory or insightful material.

"It seems to me this is an outrageous case of shifting goalposts.

"What is also beyond belief is that the detention period has been extended twice, to a total 45 days supposedly to check their seized technical equipment.

"Their equipment was no more than what any competent journalist would carry - mobile telephones, computers and sound equipment.

"This surely is one of the most extreme cases of abuse of not only a journalist's right to simply report but also on basic human rights and free speech."

Mrs Greste said a colleague had been able to wave to Peter during his appeal last night and received a thumbs up and "big smile".