The unlicensed doctor at the centre of the HIV outbreak in Battambang province was yesterday charged with murder, police and court officials said.

After questioning that began on Sunday, Yem Chroeum confessed to reusing needles on his patients and telling a family member to destroy medical waste before police could seize it, said Chet Vanny, deputy Battambang provincial police chief.

“Yem Chroeum confessed to ordering his son-in-law to burn evidence behind his house,” he said. “He also said that he treated patients with negligence and used the same needles to treat them. He’s a doctor without qualifications who has learned [basic] skills at the Cambodian-Thai border.”

Chroeum – who faces life in prison if convicted – was also charged with “intentionally” transmitting HIV and running a clinic without permission from the Ministry of Health, said provincial prosecutor Nuon San.

“Yem Chroeum was charged with three counts [including] murder . . . I have asked the investigating judge to hold him in pre-trial detention,” he said.

Heng Luy, the investigating judge, could not be reached, but Vanny said Chroeum had been sent to the provincial prison. At least 119 cases of HIV have been confirmed in Sangke district since a 74-year-old man tested positive in Roka village in late November. Despite the murder charges, there are no confirmed reports of someone dying.

From the outset, villagers have believed that routine injections from Chroeum, administered to at least 30 people, were the source of the infections. In one family, 15 out of a possible 16 have tested positive for HIV.

A search of Chroeum’s home last week uncovered used and unused syringes stored indiscriminately. While a relative has said Chroeum himself has HIV, Vanny said yesterday that tests had cleared the unlicensed doctor of infection.

“But in the past, he went to Phnom Penh to have his blood tested for AIDS under different names,” he said.

The man accused of destroying evidence, the unlicensed doctor’s son-in-law Chhem Choeun, 32, said yesterday that he often burned medical waste in a hole behind the family’s home.

“I always burn it when it is full. But I forget the last time I did it,” he said.

A source close to the case who asked not to be named said it was not yet possible to determine how many people Chroeum may have directly infected, if in fact he was guilty of doing so.

Further tests and investigation would likely determine who had contracted the virus during the first wave of infections. But doubts remain about the possibility of so many people being infected by one doctor’s needles.

Dr Edward Mills, a researcher from the British Columbia Centre for Excellence in HIV/AIDS in Canada, said reusing needles “would almost certainly not lead to this many infections”, referring to the roughly 30 people reported to have been injected.

Authorities search through evidence and the area surrounding Yem Chroeum’s house last week in Battambang’s Sangke district. Heng Chivoan

“Needles typically run a low risk of infection, the risk is about one in 10,000,” he said.

As the criminal investigation quickly turned into court proceedings yesterday – at a speed not unfamiliar in Cambodia’s much-criticised justice system – those involved in a parallel “forensic” investigation, led by the Ministry of Health, were stepping up efforts to determine the cause of the infections.

A number of people were being trained to help with that investigation, said Marie-Odile Emond, country director of UNAIDS, which is among the partners working with the ministry. “The [forensic] one is to identify the mode of transmission, how people are infected . . . interviewing a sample of people,” she said. “At this stage, it will be a minimum of a few days, but it could be longer . . . possibly a few weeks.”

Dr Masami Fujita, a medical officer with the World Health Organization, said charges being brought against a suspect did not affect the ministry’s investigation.

“This is a health assessment . . . because we do not know, it could be a combination of things,” he said. “In any case, we have to continue. We need to independently assess [the situation].”

While Fujita said the investigators on his side were communicating with the police, Dr Mean Chhivun, director of the National Centre for HIV/AIDS, Dermatology and STDs, said otherwise.

“We are not talking to the police,” he said. “The investigation is ongoing.”

James McCabe, operations manager at the Phnom Penh-based Child Protection Unit, said court officials would certainly review the ministry’s findings.

“They will consult with the Ministry of Health,” he said.

Yim Sovann, opposition spokesman and lawmaker, said police and the courts had a duty to investigate and charge anyone carelessly spreading HIV.

“But we ask the Ministry of Health to improve the situation [for the future]. The Ministry of Health has to check every private clinic to ensure ethics are upheld, doctors have degrees and everyone has a licence from the ministry,” he said.

ADDITIONAL REPORTING BY SARAH TAGUIAM