Imprisoned Australian pro-democracy activist Hiep Tran has told his family he never crossed the border into Vietnam, with supporters alleging it is more evidence he was abducted by Vietnamese authorities a month ago.
Australian officials were able to meet Mr Tran last Thursday at the B34 detention centre in Ho Chi Minh City, where he is being held after disappearing in Cambodia on September 18.
His wife, Chloe Dang, said Australian officials passed her a brief message from her husband which read: "Hi, how are you all going? I want you to know that I never entered Vietnam on my own."
"I never crossed the border. I am struggling mentally — traumatised and terrified by the situation."
That contradicts the account of Vietnamese authorities, who said that Mr Tran and another human rights activist, Norwegian citizen Duc Thuan Nguyen, tried to illegally enter Vietnam to engage in "terrorist and sabotage activities".
Mr Tran is a member of Viet Tran, an overseas Vietnamese opposition group that Vietnam's ruling party has labelled a terrorist organisation. However, most scholars say it has evolved from its armed anti-Communist roots into a political party committed to peaceful change.
Hiep Tran is imprisoned in Ho Chi Minh City after disappearing in Cambodia. (Supplied)
The group alleged the message showed that Hiep Tran and Duc Thuan Nguyen — along with a third activist — were "abducted in Cambodia by the Vietnamese authorities and forcibly taken to Vietnam, where they are being detained".
Ms Dang said in a statement that she had "received a few fragmented details" about her husband's condition from Australian officials after the visit.
"I was told that he is in a fragile mental state, gripped by fear, and experiencing erratic blood pressure, none of which he had ever experienced before," she said.
Ms Dang told the ABC that Australian consular officials were able to hand over fresh clothes to her husband, as well as verbally conveying messages from both her and Mr Tran's mother.
They were also able to show Mr Tran a family photo — although he was not allowed to keep it.
She also said Vietnamese prison officials kept strict limits on the discussion, saying they warned Australian consular officials would be kicked out if they discussed topics outside those approved by Vietnamese authorities.
And she said Vietnamese authorities were still yet to provide Mr Tran with the details of the charges against him.
The vigil in Sydney called for the release of Hiep Tran and Duc Thuan Nguyen. (Supplied)
Small groups of Vietnamese community members and activists gathered in Sydney on Saturday night to hold a candlelight vigil for Mr Tran and the two other activists who disappeared in Cambodia. A similar event is also being organised in Melbourne.
Ms Dang said Sunday marked "exactly one month since this terrible ordeal began for my husband".
"Over the past month, the Australian Government has provided tremendous support to me and my family, and I am deeply grateful," she said.
"However, I sincerely hope that the Australian government, along with people around the world, will continue to speak up and do everything possible to help bring my husband home safely and as soon as possible.
"No-one, whether an Australian citizen or anyone else, should ever have to endure the terrible ordeal that my husband and our family are going through."
Vietnam's embassy did not respond immediately to questions from the ABC about the latest developments in Mr Tran's case.
But it said in a statement last week that the kidnapping allegations were "unfounded and misleading" and that "arrests and prosecutions are carried out in accordance with the law" in Vietnam.