Ten people have been diagnosed HIV-positive in the past two weeks out of a population of 1,000 in Peam village, around 35 kilometres from Phnom Penh, the Cambodia Daily reported Monday.
The unusual profile of the patients, such as old age and monogamy, raised a red flag with provincial health authorities.
Health officials visited the village at the weekend, Health Minister Mam Bunheng told dpa on Monday, declining to discuss details, saying it would "only create chaos."
Residents blamed contaminated needles used by a local doctor, the Cambodia Daily reported.
In December, an unlicensed medic was sentenced to 25 years in prison for transmitting HIV to 270 people through contaminated needles in a village of Battambang province, 250 kilometres north-west of Phnom Penh.
The preference for medication administered by injection and poor medical training raises the risk of HIV transmission in local medical facilities.
Cambodia has slowed HIV transmission since its peak in the late1990s, but there are still 75,000 people living with the virus in a population of 15 million, according to UNAIDS.
- DPA