One of the three al-Jazeera journalists jailed in Egypt, Peter Greste, has landed in Cyprus after being deported from Egypt following 400 days in jail, his brother has told the Guardian.

Mike Greste confirmed that the Australian journalist had arrived in Cyprus and said he would issue a full statement later on. An interior ministry spokesman had earlier confirmed Peter Greste’s deportation under a recently enacted decree.

“A presidential decree has been issued to deport him to continue his punishment period in Australia. The foreign ministry co-ordinated with the Australian embassy and his plane took off at 4.10pm [local time],” he said.

The decree allows foreign detainees to continue their detention in their home countries, and is thought to have been enacted with the journalist’s case in mind.

Greste’s family did not respond to requests for confirmation.

The family of Mohamed Fahmy, Greste’s Canadian co-defendant, said on Sunday that there was no news about Fahmy’s fate, though he also applied for deportation earlier this month, and his fiancee Marwa Omara told Reuters she was optimistic. “His deportation is in its final stages. We are hopeful,” she was quoted as saying.

The pair’s colleague, Baher Mohamed, is ineligible for deportation as he only holds an Egyptian passport.

His brother Assem told the Guardian: “Baher will not be released. Until now, only Peter … but as always [with] what happens in Egypt, it’s the Egyptians who pay.”

On Sunday Mostefa Souag, acting director general of al-Jazeera Media Network, said the organisation would not rest until Greste’s colleagues were also freed, and called on the Egyptian authorities to “finish this properly”.

“We’re pleased for Peter and his family that they are to be reunited,” he said. “It has been an incredible and unjustifiable ordeal for them, and they have coped with dignity. Peter’s integrity is not just intact, but has been further enhanced by the fortitude and sacrifice he has shown for his profession of informing the public.

“We will not rest until Baher and Mohamed also regain their freedom. The Egyptian authorities have it in their power to finish this properly today, and that is exactly what they must do.”

The three al-Jazeera journalists have been in jail for over a year, after being arrested in late December 2013. In that time, Fahmy has developed a chronic shoulder condition after failing to receive adequate treatment for an injury sustained shortly before his arrest. His lawyers, who he now employs independently of al-Jazeera, say he urgently needs treatment for both his shoulder and hepatitis C.

Greste and his co-defendants were subsequently convicted in June 2014 on charges of aiding terrorists, belonging to the banned Muslim Brotherhood opposition group, and making false news, after a trial that human rights groups and journalists denounced as comically flawed.

Evidence presented by the prosecution included a song by the musician Gotye, footage of trotting horses, and a press conference in Kenya.

Earlier this month, an appeals judge appeared to recognise those flaws, sending the case to retrial. But he refused to release the trio on bail – prompting Fahmy and Greste to announce plans to seek deportation.

In the international arena, where the trio’s fate has become a cause celebre, observers view the case as a politicised attack on the freedom of expression, and part of a rampant crackdown on all forms of Egyptian opposition.

The trio are among at least 16 journalists and – according to the police’s own figures – at least 16,000 political prisoners currently detained in Egypt. Independent estimates put the figure at nearly 40,000.

But inside Egypt, many government supporters see the journalists as a legitimate target, since the coverage of al-Jazeera’s Arabic sister channels has strongly favoured Brotherhood viewpoints, while the channels’ owner, the state of Qatar, has given financial and logistical support to the group itself.

Through his family, Fahmy has also portrayed himself as a pawn in a cold war between the two countries. But relations are gradually improving between them, culminating in Qatar’s closure of the Egyptian wing of al-Jazeera last month, a move which raised hopes that the trio might be released in a reciprocal gesture by Egypt.