They are both demanding $158,300 in damages after the error was discovered when the ex-husband of one of the mothers, Yuliya Belyaeva, had a DNA test after he refused to pay maintenance for their daughter, Irina, because he didn't think the 12-year-old girl looked anything like him.

Yuliya told BBC News: "We did two DNA tests. Both tests showed that neither my ex-husband nor I were Irina's biological parents.

"The judge couldn't believe it. She said she'd only seen cases like this on TV and didn't know what to advise us."

Investigators working on behalf of the couple tracked down their actual daughter, but both girls are keen to stay with the parents who have raised them.

Yuliya added: "It's terrible for both of them. They've grown up with one set of parents, now they've found out they have a different mother and father.

"Neither child wants to leave their home. Irina keeps saying to me, 'Mum, please don't give me away!' I comfort her by saying, 'I would never do anything against your wishes. Nothing has changed. I'm still your mother.'

"As for Anya, my biological daughter, she also says she wants to remain with the parents she knows. She will just visit from time to time."Two families in Russia are suing a hospital after being given the wrong babies 12 years ago.

They are both demanding $158,300 in damages after the error was discovered when the ex-husband of one of the mothers, Yuliya Belyaeva, had a DNA test after he refused to pay maintenance for their daughter, Irina, because he didn't think the 12-year-old girl looked anything like him.

Yuliya told BBC News: "We did two DNA tests. Both tests showed that neither my ex-husband nor I were Irina's biological parents.

"The judge couldn't believe it. She said she'd only seen cases like this on TV and didn't know what to advise us."

Investigators working on behalf of the couple tracked down their actual daughter, but both girls are keen to stay with the parents who have raised them.

Yuliya added: "It's terrible for both of them. They've grown up with one set of parents, now they've found out they have a different mother and father.

"Neither child wants to leave their home. Irina keeps saying to me, 'Mum, please don't give me away!' I comfort her by saying, 'I would never do anything against your wishes. Nothing has changed. I'm still your mother.'

"As for Anya, my biological daughter, she also says she wants to remain with the parents she knows. She will just visit from time to time."