The Supreme Court in Russia's Chechnya region has rejected an appeal by the chief of the human rights group Memorial's office in Grozny, Oyub Titiyev, against the extension of his pretrial detention until June 9.
Memorial said that in a May 4 ruling, the top regional court upheld a lower court's April 25 decision to keep Titiyev in jail on a marijuana-possession charge he and supporters say was fabricated.
The 60-year-old Titiyev has been in pretrial detention in Chechnya since his arrest on January 9.
Titiyev was stopped and detained by police while in his car. Chechen authorities later said drugs had been found in his vehicle.
Titiyev and Memorial deny the charge, contending that the marijuana was planted in his car.
Western governments and human rights groups in Russia and abroad have demanded Titiyev's immediate release, saying the case against him is politically motivated.
If convicted, Titiyev faces up to 10 years in prison.