The brother of Australian journalist Peter Greste has been able to visit him in a Cairo jail, while his parents renew calls for his release.

The brother of Australian journalist Peter Greste has been able to visit him in a Cairo jail where he awaits trial for “airing false news”.

The Al-Jazeera journalist is due to face trial on Thursday, accused of backing the black-listed Muslim Brotherhood and portraying Egypt in a state of civil war.

His parents Lois and Juris Greste, based in Brisbane, have renewed calls for his release, saying he is innocent and has only been detained for producing balanced reports.

Mrs Greste says her son Andrew has visited Peter at Cairo’s high-security Tora Prison, where he is being kept in solitary confinement, and they were about to briefly speak with him about Peter’s condition.

“Last night he was able to visit Peter in prison, which is absolutely a huge relief to us and to Peter,” she told AAP on Tuesday.

“He’s doing as well as we can expect during the circumstances.”

Mr Greste added: “As you can imagine, after not having contact with anybody for two to three weeks, seeing his brother would give you kind of a stratospheric lift.”

The Grestes said they hadn’t been able to speak with Peter themselves for more than a month.

Peter Greste was arrested alongside his Al-Jazeera news colleagues in a hotel in Cairo on December 29.

Mrs Greste said the only contact they have had with him since then were brief calls he was able to make from a consular phone in the prosecutor’s office in Cairo.

Global pro-democracy group has collected the signatures of more than 30,000 Australians, which are being sent to Egypt’s armed forces chief Abdel Fattah al-Sisi, who is widely expected to stand for president.

Mr Greste said he had a simple plea for the lawmakers and “good people” of Egypt: “Please release at the absolute earliest opportunity Peter, who is entirely innocent of any of the charges and all allegations against him.”

Prosecution documents show Peter Greste and his colleagues are accused of “airing false news aimed at informing the outside world that the country was witnessing a civil war”.