Hazem Hamouda, the Australian man jailed in Egypt for a year without charge or evidence, has been prevented from leaving the country despite his release from prison.

Hamouda, a 54-year-old IT consultant from Queensland, was arrested on 25 January 2018 on arrival at Cairo international airport when he travelled to Egypt for a holiday with his family. He was accused of being associated with the Muslim Brotherhood and spreading false news on social media.

Last month the Egyptian prosecutor general ordered his release from the notorious Tora prison but he disappeared. His family located him a week later in a police cell, and on Wednesday secured his release and took him to the airport.

But authorities in Egypt have refused to let him leave despite being accompanied to the airport by Australian consular staff.

A spokeswoman for Australia’s foreign affairs department said it was “providing consular assistance” to Hamouda.

Peter Greste, the Australian journalist who was jailed in Egypt, said Hamouda was told he could not leave because he did not have the correct Egyptian documents –papers which had been confiscated and allegedly lost by authorities.

Hamouda has denied the allegations against him. His family have speculated they may relate to Facebook posts he made during the Arab Spring in 2011.

“There’s no formal evidence and we’ve been trying to rack our brains why they took Dad. That’s the only possibility we can come up with, but even then it’s not really a reason to arrest someone,” his daughter Lamisse said last month.

Upon his arrest, Hamouda’s family were told that his detention was likely part of mass arrests made around the 25 January anniversary of the Arab Spring uprising and he’d be released soon. But more than a year later he remained in an overcrowded tiny cell.

Greste, who himself spent 400 days in the prison on similar charges, called on Australian authorities to bring private and public pressure on Egypt to ensure Hamouda’s safe return.

“Hazem Hamouda’s case it deeply troubling on a host of levels. The fact that he has been held in an Egyptian prison for so long, without trial, and without any obvious evidence has been a travesty from the outset. That he should be restrained from leaving the country after being released is an outrage,” said Greste.

“The Egyptian judicial system wants to be treated with respect, and its judgments trusted. That can’t happen as long as people like Hazem are treated without due process, and as long as there is complete opacity about the decisions and actions of the system. The effectiveness of any judiciary depends on public confidence, and Hazem’s treatment works against that.”

Greste said he believed that the continued involvement of the foreign affairs minister in his case, and the presence of an Australian ambassador standing by him until he was on a plane, were “crucial” in getting him home safely.