Australian economist Sean Turnell remains in detention, Myanmar authorities have told Australia's foreign affairs officials following reported Cambodian government statements he had been freed.
Prof Turnell, a former advisor to ousted Myanmar leader Aung San Suu Kyi, has been detained for a year after his arrest following last year's February 1 coup.
He has been charged with violating Myanmar's immigration and official secrets acts by trying to leave the country with sensitive financial information and is facing a 14 year jail term.
According to the official Agence Kampuchea Presse on Monday, Cambodian Prime Minister Hun Sen said he welcomed Prof Turnell's release by junta leader Aung Min Hlaing, which followed his request on behalf of Australia.
"I want political prisoners to be released, ceasefire, assistance, and dialogue there," AKP quoted Hun Sen as saying.
In a separate report by the government-friendly Fresh News service, Hun Sen was quoted as saying: "The release is indeed to the senior general's credit, but at least I also contributed as the rotating chair of ASEAN."
But a Department of Foreign Affairs and Trade spokesperson told AAP in a statement on Monday night that Myanmar authorities had advised DFAT that "Professor Sean Turnell remains detained".
"The Australian government repeats its call for Professor Turnell's immediate release, and for his rights and welfare to be upheld," the statement said.
Pressure has been mounting on the junta to release Prof Turnell since Hun Sen became the first leader to visit Myanmar since the coup in an attempt to move an ASEAN-backed Five-Point Consensus forward.
"Professor Turnell's detention is unjust, and we reject the allegations against him," Foreign Minister Marise Payne said in a statement on Sunday.
Cambodian Foreign Ministry spokesperson Chum Sounry said earlier that the ASEAN Chair's special envoy, Cambodian foreign minister Prak Sokhonn, hopes Myanmar's senior general honours his assurances to Hun Sen.