An Australian activist and two others have been charged by Vietnamese police with “terrorism” and “forging documents”, according to his supporters.

Tran Hiep, a member of pro-democracy diaspora political party Viet Tan, had been due to join his wife in Bangkok after travelling to Phnom Penh, Cambodia.

Hiep, who founded the Australian Alliance to Combat Human Trafficking, was travelling with Vietnamese-Norwegian human rights activist Nguyen Duc Thuan to meet dissident Vietnamese activists for training in Cambodia.

But the 50-year-old Melbourne man did not board his flight and has not been heard from since September 18.

Vietnam’s Ministry ‌of Public Security said the pair, along with a third person, had been detained on September 18 and were accused of illegally attempting to enter Vietnam from Cambodia to “conduct terrorist and sabotage activities”.

In an update on Tuesday night, Viet Tan said via social media that the ministry had decided to prosecute Hiep and two others on charges of “terrorism” and “forging documents of agencies or organisations”.

When the two Viet Tan members (Thuan and Hiep) were first arrested, the activist group accused Vietnamese authorities of kidnapping and abduction and claimed the men had no intention of entering Vietnam.

They now claim the ministry’s latest statement contains “inconsistencies”.

“[The ministry] stated that authorities discovered and apprehended the three men at the Tay Ninh border at exactly 9.50pm on September 18,” Viet Tan said on social media.

“This was the exact time when families in Norway and Australia lost contact with the two activists after they had left their hotel in Phnom Penh. The two men were scheduled to take a return flight to Thailand on September 19 before flying back to Europe and Australia.

“What reason could possibly cause two citizens to miss their flights home to their families in favour of trekking secretly across border trails in Tay Ninh in the dead of night?”

Viet Tan alleged authorities were fabricating the charges to “cover up an act of transnational repression”, accusing Hanoi of “conduct … no different from that of common thieves and bandits”.

“They seek to eliminate activists yet act with cowardice, terrified that their true nature will be revealed to the international community,” the group said.

Asia Human Rights and Labour Advocates director Phil Robertson said the arrests demonstrated Vietnam’s president, To Lam, was “presiding over a ruthless police state that shows no hesitation in running roughshod over human rights while simultaneously seeking to expand its business links with the world”.

“The international community needs to realise that continuing business as usual with Vietnam is not acceptable when Hanoi is expanding its transnational repression efforts wherever it deems fit,” he said.

Viet Tan and Robertson are calling on Norwegian and Australian authorities, and human rights organisations, to press the Vietnamese government for the immediate and unconditional release of both men.

Hiep’s wife, Chloe Dang, said she feared for her husband’s life. “My family and I are really worried about his safety, and we just only want to know where he is and what happened to him,” she told AAP from Bangkok airport before boarding a flight to Melbourne.

“My husband deserves protection, and I really hope the Australian government will continue to put pressure on Cambodia to do an investigation to find out where he is right now.”

Dang, 36, said her husband’s disappearance had taken a psychological toll.

“It’s been 11 days and I’m really in the dark,” she said before the news from Vietnam, choking back tears. “I don’t know where he is and how he’s doing – it’s driving me crazy. Everything is really uncertain.”

The Australian government confirmed that consular officials were in contact with Dang, but declined to comment further.

“The Department of Foreign Affairs and Trade is providing consular assistance to the family of an Australian reported missing in Cambodia,” a department spokesperson said.

The families of the missing men have filed an appeal with the UN Working Group on Enforced or Involuntary Disappearances.

Vietnam has stepped up its crackdown on dissidents in recent years, and more than 55 activists have been arrested under broad criminal laws in 2025.

Civil society groups and United Nations human rights experts have repeatedly warned of growing co-operation between Vietnamese authorities and neighbouring governments targeting activists.

AAP, Reuters with Alexander Darling

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