A former Cambodian MP was shot dead by a motorcyclist near Wat Bowonniwet Vihara in Phra Nakhon district of Bangkok on Tuesday evening.
Lim Kimya, 73, died at the scene. Police have launched a manhunt for the assassin.
Surveillance camera video from the scene showed a man riding a red Honda Wave motorcycle, licence plate number 845, wearing a helmet, long jeans and a grey short-sleeved shirt with a bag across the front. It is believed that a gun was hidden in the bag.
The deceased, who held Cambodian and French nationality, had reportedly travelled to Bangkok by bus from Siem Reap, Cambodia, with his French wife and Cambodian uncle.
The shooting took place shortly after they arrived at the scene, according to police. The perpetrator rode up on a motorcycle, parked it and got off to shoot. He then rode away along Phra Sumen Road, passing in front of Wat Bowonniwet, police said.
Lim Kimya was a member of the Cambodia National Rescue Party, which was the main opposition party in Cambodia before it was dissolved by the Supreme Court in November 2017.