A new set of security measures at Prey Sar prison, designed to stop rampant drug use at the facility, is instead being selectively applied to prisoners being held in a politically sensitive case related to an ongoing sex scandal involving opposition leader Kem Sokha.

Prison authorities have used glass partitions in the visiting area to keep Yi Soksan and Nay Vanda – jailed human rights workers from Adhoc – from having physical contact with their loved ones, the detainees’ families have said, while visitors to other inmates said they had been able to interact freely with those they had come to see.

Nuth Savna, spokesman for the Interior Ministry’s General Department of Prisons, said the partitions stemmed from a policy implemented in recent months to prevent drug exchanges between prisoners and visitors after the government’s own probe found detained in April, and have been charged with conspiring to bribe Khom Chandaraty, the alleged mistress of opposition leader Kem Sokha, to deny her affair with the Cambodia National Rescue Party’s acting president.

The case has been widely slammed as politically motivated. In a statement yesterday, Tokyo-based group Human Rights Now (HRN) expressed its grave concern over the group’s detention.

All five of the detainees have been classified as “political prisoners” by rights group Licadho.