The senior Australian military official in charge of coordinating the resettlement deal with Cambodia visited Phnom Penh late last week to finalise arrangements for the transfer of four refugees to the Kingdom, he told a Senate committee this week.

Major General Andrew Bottrell, commander of the Joint Agency Task Force for Operation Sovereign Borders and the “tactical and operational liaison with the government of Cambodia”, told Australia’s legal and constitutional affairs committee on Monday that a final date for their arrival had not yet been set.

“I cannot give you a final date, because we have not finalised that with the government of Cambodia,” he said, according to an official record of the proceedings.

“I returned from Cambodia at the end of last week. We continue to work very closely with the government of Cambodia to finalise the arrangements for the final movement of those four.”

Four refugees – an ethnic Rohingya from Myanmar and three Iranians – were secretly flown from the Pacific island of Nauru to Darwin in Australia’s Northern Territory in early May and have been housed in an immigration facility near the airport ever since, awaiting approval for a flight to Cambodia.

Since the resettlement scheme, signed in September, was first raised in a closed-door meeting between Australian Foreign Minister Julie Bishop and Prime Minister Hun Sen in February last year, it has been shrouded in secrecy. “Consistent with the established protocols for information relating to international engagements, the detail of official bilateral dialogue or communication between operational agencies relating to Operation Sovereign Borders will not be disclosed,” Bottrell said.

Australia agreed to provide an additional A$40 million (about US$31 million) in aid to Cambodia as part of the arrangement, and earlier this week announced it would spend an estimated A$15.5 million more to fund resettlement services.

Bottrell told the committee that the country’s militarised offshore refugee policy had allowed him to focus various agencies’ resources on the deal.

Mike Pezzulo, secretary of Australia’s Immigration and Border Affairs Department, told the same committee on Tuesday that the secrecy was because Canberra does “not want [the refugees] to become zoo exhibits”.

“They are being managed sensitively and empathetically. People have been with them caring for them and engaging with them whilst they have been in transit, and we look forward to helping them to get on their way and settle in Cambodia in the not too distant future.”

“It is just a matter of working through some final logistical details,” he added.

The International Organization for Migration (IOM), which is providing initial accommodation for the refugees and some services, yesterday suggested that media access to the group would not be forthcoming.

“Media exposure could potentially jeopardise protection needs of refugees and carries high level of risk to their families at home,” an IOM spokesman said. “While IOM can speak in general terms about what services will be available to refugees, IOM will not disclose any specific details about a refugee’s particular assistance.”

The group said last week that it had “villa-style” accommodation in Phnom Penh readied for the arrival of the four.

Foreign Ministry spokesman Koy Kuong said Major General Bottrell would have met directly with senior Interior Ministry officials during his visit, as the Foreign Ministry had not been informed. Interior Ministry spokesman Khieu Sopheak could not be reached.

Pezzulo said Australia hoped that Cambodia would take, on a voluntary basis, “as many [refugees] as possible – as many as the Cambodians are willing to take, as many who seek to settle there and as many as can be processed accordingly”.

David Manne, executive director of the Australia-based Refugee and Immigration Legal Centre, said secrecy had plagued the agreement since day one.

“This secrecy is also deeply troubling given that under this cynical, short-term political fix, Australia is aiding, abetting and funding the diversion of refugees in its care to a country – Cambodia – which is a deeply impoverished country engulfed in a human rights crisis … a completely untenable place to resettle refugees.”