Two Iranian refugees, brought to Cambodia under a resettlement deal with Australia, have gone back to Iran, meaning just two of five people who have moved to the Kingdom under the controversial A$55 million (US$41 million) scheme remain in the country.

Director of the Interior Ministry’s Refugee Department Kerm Sarin said the pair, an Iranian couple in their 40s who were among the first four arrivals who touched down in June 2015, had returned home on February 12.

“They volunteered to go back. They didn’t [give] any reason. They went back to their hometown. It was a man and a woman; they didn’t say they were unhappy. They have a right to stay or to leave, so if they enjoy staying in Cambodia, they stay; if they don’t want to, if they want to go back home, it’s up to them.”

The pair’s departure comes after another of the June arrivals, reportedly a Rohingya man from Myanmar, also chose to return home in October because he was “homesick”, according to a government official at the time.

Now only two refugees from Nauru remain in Cambodia – a young Iranian man who was among the first four, and another ethnic Rohingya man from Myanmar, secretly transferred from Nauru to Phnom Penh in November.

The Australian Embassy in Cambodia did not respond to requests for comment.

Joe Lowry, spokesman for the International Organization for Migration, contracted to help integrate and provide for the refugees in Cambodia, yesterday declined to comment, citing confidentiality clauses.

Ian Rintoul of the Australia-based Refugee Action Coalition, called the deal a “farce” and said he expected the remaining Iranian, who is in his 20s, would follow.

“Cambodia was only ever a stopping off point, none intended to stay in Cambodia, it was a way of getting to somewhere else,” Rintoul said.

“The Australian government is willing to spend tens of million of dollars to try and prop up off-shore processing, but this shows conclusively that there is no resettlement program from Nauru.”

Denise Coghlan, director of the Jesuit Refugee Service in Cambodia, said the improved political situation in Iran, following the lifting of sanctions on the country in January, could have influenced the pair’s decision.

Under the resettlement deal, inked in 2014 and heavily criticised by refugee advocates, Cambodia agreed to take refugees held by Australia on the Pacific Island of Nauru in exchange for A$40 million in aid and another A$15 million to cover resettlement.

But, despite being offered cash incentives, all but five have refused to leave the island, where 484 refugees and asylum seekers currently reside, according to figures from the Australian government, which has declared no refugees who come by boat will be settled in the country.

Sarin, from Cambodia’s refugee department said that at this stage, there were no more volunteers seeking to resettle in Cambodia but wouldn’t offer an opinion as to whether the majority of refugees returning home meant the scheme was a failure.

“We are doing a humanitarian program, so whether it’s successful or unsuccessful, it doesn’t matter, as long as we have implemented the MoU.”

With its Cambodia and Papua New Guinea resettlement programs failing to attract interest, Canberra is in discussions with several other countries – including Malaysia, the Philippines and Indonesia – to resettle its unwanted refugees.