Bishop spoke to Egyptian leader about detained journalist

The parents of an Australian journalist detained in Egypt say Foreign Minister Julie Bishop has spoken to the country's prime minister about their son's plight.

Peter Greste (File: Getty)

 Peter Greste is one of 20 AlJazeera journalists who has been referred to trial for "airing false news" and stands accused of misleading outside viewers about the situation in Egypt.

Mr Greste's mother Lois said the weeks since her son's arrest in late December were the most harrowing of her life, and thanked the Department of Foreign Affairs and Trade for their assistance.

She said Ms Bishop had phoned Egypt's prime minister on their son's behalf, but would not elaborate on the  details.

"I am able to tell you now that Julie Bishop had a long phone call with the Egyptian prime minister," she said.

Confirmation and comment has been sought from Ms Bishop's office.

Greens leader Christine Milne urged Prime Minister Tony Abbott to follow US Secretary of State John Kerry's lead and speak out on the journalist's behalf.

"If it's good enough for John Kerry to speak out, it's good enough for Tony Abbott to speak out," she said from Melbourne.

Egyptian prosecutors have referred to trial 20 journalists working with Al-Jazeera television network, including four foreigners accused of "airing false news".

The 16 Egyptians have been charged with belonging to a "terrorist organisation...and harming national unity and social peace," the prosecution said in a statement.

The four foreigners -- two Britons, an Australian and a Dutch national -- have been accused of "collaborating with the Egyptians by providing them with money, equipment, information ... and airing false news aimed at informing the outside world that the country was witnessing a civil war."

Of the 20, only eight are in detention, while others are being sought by authorities.

The prosecution did not reveal the identities of those being detained, but on December 29 three Al-Jazeera journalists -- Peter Greste, an acclaimed Australian reporter who formerly worked for the BBC, Canadian-Egyptian Mohamed Adel Fahmy and Egyptian producer Baher Mohamed -- were arrested in a Cairo hotel.

The prosecution had previously accused the Al-Jazeera crew of having links with the Muslim Brotherhood, which has been blacklisted by the military-installed authorities as a terrorist group.

The blacklisting move is part of a deadly government crackdown on the Brotherhood since the July ouster of president Mohamed Morsi, who hails from the movement.

The blacklisting of the Brotherhood makes promotion of the group either verbally or in writing punishable by lengthy prison sentences.