Image copyright Getty Images Image caption Prince Norodom Ranariddh and his wife Ouk Phalla were due to meet political supporters

A Cambodian prince and former prime minister has been injured and his wife killed in a head-on car collision in the south-west of the country.

A taxi hit the vehicle Prince Norodom Ranariddh, 74, and Ouk Phalla, 39, were travelling in, officials say.

The couple were taken to a local hospital in the Preah Sihanouk province, but Ms Phalla died a few hours later.

They were travelling to meet political supporters when the crash happened.

Prince Ranariddh, the half-brother of King Norodom Sihamoni, leads a political party that is contesting next month's controversial general elections.

Last year, the country's main opposition party, the Cambodia National Rescue Party (CNRP), was dissolved and its leader was charged with treason.

Prime Minister Hun Sen has ruled the country for 33 years and has long been accused of using the courts and security forces to intimidate opponents and crush dissent.

Prince Ranariddh served jointly with Mr Hun Sen as Cambodia's prime minister from 1993 to 1997, when he was ousted in a coup led by the current prime minister.

The prince made a political comeback in 2015 after reconciling with Mr Hun Sen.