Amnesty International is sending out an SOS over the closing down of its office in Moscow.
Staff arrived at work to find the locks had been changed, the power cut off and official seals placed over the doors.
The Moscow city council, which owns the building, claims the group is behind in its rent. But Amnesty claims it is all paid up.
Sergei Nikitin, the head of Amnesty International in Russia, told reporters: “We totally do not understand what has happened. We did not get any warnings. We did not get any messages via mail or email.
“And I want to stress that during more than 20 years of us renting we have always paid in time. And there can be no doubt that this is not an eviction due to missed payments.”
Amnesty, which often criticises Russian authorities, says there may have been some kind of administrative mix-up, but the move may also be part of a recent crackdown on civil society groups.