Australian Foreign Affairs Minister Marise Payne has thanked the Cambodian government for the release of Australian film maker and convicted spy James Ricketson.
"I welcome the news that James Ricketson's petition for pardon has been approved by the Cambodian government," Ms Payne said in a statement on Saturday.
"This ends a distressing time for Mr Ricketson and his family.
"I thank my counterpart, Cambodian Foreign Minister Prak Sokhonn, for his government's positive consideration of Mr Ricketson's petition."
Ricketson, 69, was jailed for six years on August 31, but on Friday received a royal pardon from Cambodian King Norodom Sihamoni.
The film maker was convicted for espionage and crimes endangering Cambodian national security after flying a drone over a political rally organised by the now banned Cambodian National Rescue Party (CNRP).
The prosecution alleged Ricketson was spying for "foreign states" but declined to say which ones or call any witnesses to substantiate the charges. However, they did produce evidence tying Ricketson to former CNRP leader Sam Rainsy.
The trial was widely criticised by human rights activists and politicians in Australia.
The Labor party's foreign affairs spokeswoman Senator Penny Wong also welcomed the pardon.
"We were deeply concerned by his conviction and the severity of his sentence, and by the effect this would have on Mr Ricketson's wellbeing and health," Ms Wong said in a statement on Saturday.
Mr Ricketson's family have expressed their relief at his release, with his son Jesse thanking the king for "showing us compassion and bringing this nightmare to an end".
"It still hasn't really sunk in. It has been a really tough 16 months and I'm just kind of in shock right now," Jesse said.
Mr Ricketson's lawyer, Kong Sam Onn, said legal papers required for his release had been issued and his client could be bound for Australia shortly.
He said Ricketson had been released from jail on Friday evening and was heading to his son Jesse's house in Phnom Penh.
It is expected he will depart Cambodia on Saturday.
Senator Payne said she would not make further comments on the prison release, but said her department was providing consular assistance.
Australian Associated Press
