Russia's worst female serial killer Irina Gaidamachuk has been jailed for 20 years for killing and robbing 17 elderly woman with a hammer.

Dubbed 'Satan in a skirt' by Russian media, Gaidamachuk, 41, posed as a social worker to gain entry into the homes of her victims before killing them with a hammer during a seven year period.

The mother of two would also rob her victims - aged between 61 and 89 - reportedly to pay for alcohol.

Police say Gaidamachuk only stole the equivalent of £1,000 from all her victims, sometimes stealings as little as £20.

She confessed to police: 'I did it for money. I just wanted to be a normal mum, but I had a craving for drink.

"My husband Yury wouldn't give me money for vodka," she said, reported the Daily Mail.

The murders were so horrific that police originally believed the killer was a man, even thinking it may have been a man dressed as a woman.

A police source said: "We believed at first that only a man could be so cruel as to slaughter in this way."

Authorities said Gaidamachuk began killing pensioners in 2003 and was arrested in 2010 in the town of Krasnoufimsk, southwest of the capital Moscow.

A court in Yekaterinburg, Russia's fourth biggest city, deemed Gaidamachu sane when she was committed her murders.