An Australian man who was killed and another who was injured in a landmine accident at an army base in Cambodia on Thursday were not Australian defence force personnel and the explosion did not occur during a military exercise, the Australian Department of Defence has confirmed.

Cambodian authorities initially claimed the men were military trainers present at an exercise at a tank base in Kampong Speu province, about 50km from Phnom Penh, when the war-era bomb detonated. The explosion also killed one Cambodian soldier and wounded a second.

Later, Chhum Socheat, a spokesman for Cambodia’s defence ministry, said no such military exercise had been taking place and the Australians were on a “very personal visit.”

“The Australian men were invited to visit the base by the military officers at the base,” he said. “They are friends with the Cambodian military [officers] who [are] stationed there.”

Socheat said it was not clear whether the Australian who was killed was a tourist: “But obviously he was not a military exercise trainer. He was just visiting.”

“We are searching for his passport. Even the [Australian] embassy has been requesting for more details, which we could not share with [them] at the moment.”

However, other officials claimed the men were tourists.

“They apparently were just tourists visiting the base. As they approached the shooting range, one of them picked up the bomb,” said the provincial governor of Kampong Speu, Vey Samnang, who claimed one of the men had told officers he had expertise with mines.

An assistant to base commander Lanh Kao, who refused to provide his name, also said the Australians were tourists.

Another soldier at the base, who also refused to give his name, said Australian tourists regularly used weapons at the base “for fun”, though this was denied by Socheat.

The base is filled with unexploded ordnance and military officials say it is regularly used to practise demining and not open to the public.

For years, videos have circulated online apparently showing tourists in Cambodia paying to use military-grade weapons such as rocket-launchers at bases like the one in Kampong Speu.

Mam Socheat, a villager who lives about a kilometre from the base, said he regularly heard sounds of explosions coming from the site.

“[I] have noticed western people come over,” he said. “I don’t know what they have been doing inside.”