A letter from the Australian Thai cave rescue heroes and dual Australian of the Year recipients pleading for the freedom of Bahraini refugee Hakeem al-Araibi from a Thailand prison might be just the pressure needed, according to an Australian refugee law expert.

Anaesthetist and diver Dr Richard Harris with retired vet and champion WA-based diver Dr Craig Challen are the latest freedom fighters to join the campaign for the 25-year-old refugee’s release.

The exact contents of their joint letter to Thai Prime Minister Prayut are not known, but the ABC has reported the letter pleading for Mr al-Araibi’s freedom was sent days ago.

Mr al-Araibi, a soccer player based in the inner-northern Melbourne suburb of Pascoe Vale since 2017, has spent the past two months in prison. He faces extradition and a 10-year prison term for allegedly vandalising a police station in his home country of Bahrain.

He has denied the charges and says he was playing in a televised match when the vandalism occurred in 2012.

Mr al-Araibi was detained on November 27 by Thai authorities when he arrived in the country for his honeymoon.

Meanwhile, Foreign Affairs Minister Marise Payne, who also implored Thai authorities to release Mr al-Araibi when she was in the country last month, on Saturday wouldn’t tell reporters the contents of the letter the hero cave divers had sent.

Instead, she said the government had “engaged at the highest level” with the Thai government to ensure that Mr al-Araibi is returned to his home in Melbourne “as soon as possible”.

Australians of the Year Dr Richard Harris and Craig Challen. Photo: AAP

Dr Harris, from Adelaide, and Dr Challen, from Wangara in Western Australia, were part of a global rescue mission that saved 12 boys and their soccer coach from a flooded cave in July last year.

The pair risked their lives, working between 14 and 16 hours a day over an extraordinary three-day rescue operation to ensure the boys were brought out safely.

They remained in the cave until the last boys and their coach were brought to the surface and reunited with their families.

Members of the ‘Wild Boars’ soccer team inside the cave. Photo: AAP

University of New South Wales Sydney law professor Guy Goodwin-Gill told The New Daily he encouraged pleas like those from the cave heroes to the Thai government, given how the duo had helped the country during the historic cave rescue mission.

“It very often depends how issues are presented,” Professor Goodwin- Gill said. “No country likes being bullied, it can produce knee-jerk reaction, but support internationally is very important indeed.”

Professor Goodwin-Gill said he believed the Thai prime minister had the executive power to return al-Araibi.

“I would have thought they would have the power to bring the proceedings to an end, release him and allow him to return back to Australia,” he said.

“I don’t see any need for processes to go ahead – but they may not want to be seen to be interfering in legal processes,” he said, adding it could be perceived as politics “interfering with the law,” he said.

Hakeem al-Araibi fears torture and even death if he is returned to his homeland. Photo: Getty

The refugee continues to train behind bars, doing push-ups and running without shoes. He has signed for the 2019 soccer season despite looming extradition proceedings.

If bail is refused, Mr al-Araibi will be held at the Bangkok Remand Prison until at least April 22, when his pre-trial begins.

The Thai cave divers’ plea to release Mr al-Araibi follows several high-profile footballers including Gary Lineker, Robbie Fowler and Didier Drogba and former Socceroos captain Craig Foster.

Former Socceroos captain Craig Foster has fought for Hakeem al-Arabi’s release. Photo: AAP

Prime Minister Scott Morrison has repeatedly called for the refugee  to be released.

He said seeing al-Araibi in shackles had prompted him to write to his Thai counterpart a second time on Tuesday after first writing last week with the request that the refugee to be returned to Australia.

“I’m respectfully reminding the Thai prime minister that Australians feel very strongly about this – very very strongly.”

The Thai Attorney-General’s office has defended the extradition process and claims the Thai government lacked the power to stop the case.