Asher Krichevsky, the chief rabbi of Siberia and Omsk, appealed to the court last month after Russian authorities revoked his residence permit. The rabbi was not informed why his permit was annulled, the anti-extremism group Sova Center said .

The chief rabbi of Siberia faces deportation after reportedly losing a court battle against Russian authorities in a national security case shrouded in secrecy.

“The nuances of the case are unknown, but a preliminary version has it that some of his actions, threatening national security and the constitutional order, served as grounds for Krichevsky’s deportation,” the Superomsk news website reported Tuesday.

According to Sova Center, the regional Interior Ministry refused to say why the rabbi faces expulsion in the closed-doors hearing, explaining only that the decision was based on secret Federal Security Services (FSB) documents.

Krichevsky successfully appealed previous efforts to deport him in 2014.