Cambodian Prime Minister Hun Sen and five other government officials have contracted the A(H1N1) virus, also known as swine flu, the ministry of health said.
Minister of Health, Mam Bunheng, said on Tuesday that the prime minister has received treatment and is recovering.
Mam Bunheng said the six were likely exposed to the virus at the weekly cabinet meeting on last Friday.
Among the other officials infected are Deputy Prime Minister Yim Chhay Ly and two senior ministers.
Hun Sen's illness caused him to miss the 59th anniversary celebration of the founding of the ruling Cambodian People's Party, which took place Monday in Phnom Penh.
Cambodia reported its first swine-flu case in June last year, and the first death in September. The disease has since infected around 600 people in Cambodia and killed six.
The World Health Organisation's latest update from June 20 reveals the disease has killed at least 18,209 people worldwide.