Updated

Activists say authorities in Russia's Chechnya are threatening the family of a prominent rights advocate who was detained earlier this week.

Authorities are investigating Oyub Titiyev, chief of the local branch of the rights group Memorial, for drug possession, saying marijuana was found in his car after he was stopped by the police.

Memorial has described Titiyev's arrest as an attempt to muffle one of the few critics of Chechen leader Ramzan Kadyrov.

In a statement Thursday, Memorial said Chechen police officers have threatened Titiyev's family and forced them out of the house.