The US State Department has published its annual report on human rights across the globe, describing a year of shrinking freedoms and rights violations in Cambodia, as well as seemingly chronic problems of prison overcrowding and anti-Vietnamese sentiment.

Among the “most significant” violations were “arbitrary arrests”, including that of Cambodia National Rescue Party President Kem Sokha.

After Sokha’s arrest, the CNRP – which was primed to challenge the ruling party in this year’s national election – was forced to dissolve by the Supreme Court after a Ministry of Interior complaint.

“Following the arrest of Kem Sokha, nearly every senior leader of the CNRP went into hiding or exile,” the US report states.

The State Department also notes “the use of violence and imprisonment – both actual and threatened – to intimidate the political opposition and civil society as well as to suppress dissenting voices”.

The report accuses Cambodia’s judiciary of political bias and corruption, saying that the courts “could not assure due process”.

It also claims Cambodian authorities “routinely” conducted searches and seizures without warrants and tapped the phones of alleged dissidents.

The report also touches on backslides in press freedom, pointing to the closure of over a dozen independent radio stations as a prime example of the restriction of critical voices.

The report also questioned the integrity of the investigation into the assassination of government critic Kem Ley and the disappearance in June of Khmer Krom monk Meas Vichet.

“Krobei Riel [village in Siem Reap] security officials detained [Vichet and a companion], forcibly removed their clothes,

and beat them, claiming they had information on the murder of Kem Ley,” it states.

Another monk from Vichet’s pagoda, who asked not to be named, confirmed on Tuesday the “activist” monk has still not returned or been heard from.

Soeung Sen Karuna, spokesman for human rights group Adhoc, said he spoke to the monk’s companion after the incident in June, and he confirmed they were stripped and beaten.

Karuna said Adhoc and the United Nations have been investigating the incident, but have no leads as to Vichet’s whereabouts.

The State Department also singles out the country’s prison system, which has been under stress due to an ongoing drug crackdown. Facilities were deemed to “not meet international standards” due to reported beatings of inmates, overcrowding, malnutrition, disease and a lack of clean water.

Anti-Vietnamese racism, meanwhile, was also a continuing issue, with “societal animosity” widespread towards the group, which is “widely deemed a threat to the country’s political system, security, and culture”.

Repeated attempts to reach a government spokesman for comment on Tuesday were unsuccessful.