Russian broadcaster, Channel One, has blamed hackers for the leak of the final episode of series four of the BBC's Sherlock ahead of its broadcast date. 

Fans were warned of the leak by the producers who pleaded with them not to spread spoilers or images online. 

The episode had been professionally dubbed into Russian in preparation for broadcast in the early hours of Monday morning, simultaneous with the broadcast in Britain at 2100 GMT. 

A Channel One spokeswoman said that an initial investigation points to hackers as the culprits. She said the broadcaster was cooperating closely with the BBC to investigate the leak.