Cambodia opposition leader Kem Sokha was denied bail Wednesday after almost a year in jail on treason charges that critics say were trumped up by Premier Hun Sen to gift himself a free run in last month’s election, Agence-France Presse reports. The decision was made despite calls for his release for the sake of reducing tension and international pressure as over a dozen politicians and opposition activists are currently in jail. Sokha suffers from serious health problems but he has been denied appropriate medical treatment. The Human Rights Watch has called for the release of the opposition leader, citing the UN Standard Minimum Rules for the Treatment of Prisoners, also known as the Nelson Mandela Rules, that prohibit “indefinite and prolonged solitary confinement.”