David Vardanyan, the son of former Nagorno-Karabakh leader Ruben Vardanyan who who is currently incarcerated in Azerbaijan, has revealed that his father’s conditions for imprisonment have worsened since before he went on a hunger strike on April 5.

David Vardanyan said in an interview with CNN on Tuesday, April 23 that Ruben Vardanyan called a relative several days before and revealed that he had been moved to a fully isolated cell.

“Since April 2 we had not heard his voice… Tragically, we found out he had been on a hunger strike since April 5,” David tells CNN.

After Azerbaijan took over Nagorno-Karabakh, former leader Ruben Vardanyan and other Karabakh leaders was arrested on terrorism charges.