This story could very easily be out of a movie, about two Russian baby girls who were switched at birth, and more than a decade later become best friends. It would definitely be a tear-jerker.

But readers, this story is all too real, and the story begins in the Ural Mountains in Russia.

Police believe that on Dec. 17, 1998, there was a terrible mixup at the local maternity hospital. The two babies had been given the wrong name tags - and the wrong parents.

Yulia, who took Irina home and raised her, discovered the mixup 12 years later after urging her ex-husband to take a DNA test to prove his paternity, following a court battle for child support and maintenance.

"The results were a total surprise," she has admitted to the BBC.

"Not only does my ex-husband have no biological link to Irina - neither do I."

"At first I thought it was a joke," recalls Yulia.

"Then I couldn't stop crying. My whole world had turned upside down. I kept worrying what Irina would say. And I kept thinking about my real daughter. Maybe she'd been abandoned. Put in an orphanage. Or perhaps she was begging on the streets."

Babies are born helpless and need to identify who the person is to feed and protect them. They recognise their mother's voice from what they have heard in the womb. They also know her smells. Another study found they recognise the mother's face after a few hours, according to BBC sources.

If the baby is given to another mother soon after birth, that survival instinct is then transferred to whoever is the new caregiver. It would not necessarily be traumatic.

There would be a much more severe impact after a year, when they would have formed a much deeper attachment and the disruption of that bond can have lifelong consequences.

Discovering that mistake at age 12, when you are just developing a sense of identity, would be a big challenge.

Police have successfully tracked down her actual daughter Anya to a village half an hour away, living with Irina's father.

Despite being reunited, the two girls decided they wanted to stay with their non-biological families, refusing to go back to their biological families.

"I tried to show Anya motherly love, but she doesn't accept it," Mrs Belyaeva said.

"When your own daughter looks at you like a stranger, that's so painful."

The two girls have bonded following the reunion despite tension between the families.

"We were a bit shy at first but we're now the best of friends," Irina said.

The parents have faced difficulties trying to get along owing to their two different cultures, with both sides worrying about their biological child's upbringing.

In one house is Naimat Iskanderov - the man Anya thought was her father. Naimat is from Tajikistan. He had married a Russian woman, but they had divorced. It was Naimat who brought up Anya and his other children as devout Muslims. When police told him about the mistake at the maternity hospital and that Anya was not his daughter, at first he refused to believe it.

"Then the detective showed me a photo of the other girl, Irina, the one they said was my real daughter," says Naimat.

"When I saw her face, it was like seeing myself. My arms and legs began shaking. It was awful to think that my child had grown up with another family. And that I had brought up someone else's daughter."

The two families meet regularly now, but admittedly there is tension between them.

"It is difficult," says Anya's father Naimat. "One family is Christian, the other is Muslim. What I fear most is that the daughter I've raised will start going drinking in bars, that she will stop praying and working. I'm worried she will lose her religion."

"There is tension between the adults," says Yulia, "Naimat doesn't like some things that go on in our family, I don't like some things in their home. Both of us are used to life as it has been. Not as it is now. Now it is a nightmare."

The two families are now working together to sue the hospital for about $300,000 in damages.

Whether the truth can set you free is debatable. Is ignorance bliss?

I loved the following line from Anya when she was asked what she wanted:

"What I'd like," says Anya, "is for all of us to live in one big house."

The logistics aside, I really hope for a happy ending for these girls.