Cambodian Prime Minister Hun Sen on Monday ordered authorities to launch a thorough probe into the killing of a prominent political analyst.

Kem Ley, 46, director of the Organisation for Social Development, was shot dead on Sunday near a gas station in capital Phnom Penh, Xinhua news agency reported.

“I order the authorities to find out the perpetrator(s) and accomplice(s) in order to bring them for prosecution in accordance with the law,” the Prime Minister said, adding “This severely affects the reputation of the government.”

He strongly condemned the brutal act and also declared a large-scale campaign to crack down on all crimes in order to strengthen security and social order.

Meanwhile, National Police spokesman Kirt Chantharith said that a 38-year-old male suspect, whose shirt was stained with blood, was arrested with a Glock pistol shortly after the crime.

He said the suspect confessed to the crime, saying that he got furious with Kem Ley, who owed him $3,000, but did not repay him.

However, the suspect’s confession was not taken into account.