Investigative NGO Global Witness yesterday issued an open letter to Prime Minister Hun Sen asking him to ensure the independence of the investigation into slain political commentator Kem Ley’s death and to protect the rights of citizens who criticised the government.

The letter, signed by the group’s co-founder and director Patrick Alley, states that following Ley’s death last month his friends and colleagues were “threatened and intimidated”, resulting in activist brothers Chum Hour and Chum Hout seeking asylum in Thailand.

Alley calls for an independent investigation into Ley’s murder, which the letter states was part of “a long line of violence against members of the opposition, activists and journalists”.

“The early stages of the investigation into Kem Ley’s killing have done nothing to allay fears that, like the others before it, this investigation will fail to identify or prosecute those who ordered the crime,” the letter reads.

In the wake of Ley’s death, local and international bodies made similar calls for an independent and thorough investigation into the murder.

Phnom Penh municipal police chief Chuon Sovann said the police were already conducting their investigation and were making steady progress. “The authorities are working attentively and investigating the perpetrator,” he said. “We do not need any request from this institution [to do so].”

While he hadn’t read the letter, government spokesman Phay Siphan was dismissive.

“The [Global Witness Hostile Takeover] report and reasons [in this letter] are anti-government, so we do not give it any credit at all,” he said.