The death mask of Soviet dictator Josef Stalin was sold on Tuesday for 3,600 British pounds ($5,600) at British auction house Mullock’s.

The name of the buyer was not revealed, he was not present in the building and acquired the lot by telephone, Mullock’s said.

The cast is one of several copies taken from the original plaster cast after Stalin’s death in 1953.

Two copies were brought to the West in 1990 by art dealer James Birch, one of the first to break through to the emerging art market beyond the Iron Curtain. The original plaster cast is still on display at the Stalin museum in his native Gori in Georgia.

Stalin died at the age of 74 after more than two decades at the helm of the Soviet Union. The official cause of his death was a cerebral hemorrhage, but alternative theories speculate he might have been poisoned by his associates.