Lyudmila explained she had run away from a hospital, but could not explain where this was. Picture: Oksana Vasilishina

She is called Lyudmila Neizvestnaya (her adopted family name meaning 'Unknown' in Russian) by staff at the Ovsyanka mental hospital after arriving at Krasnoyarsk Airport on 30 August 2007.

Until now, no-one knew her identity, but new and disturbing information suggests she was lured by a mystery man from a faraway hospital where she was being treated.

Valentina Ivanova, a junior nurse, recalled: 'They brought her here all dirty and covered in bruises. She looked 15 or 16 years old, like a child. Her hair was short, she was skinny, flesh and bones.'

Lyudmila Dolgopolova as a teenager, soon after she was found in the airport (top) and as a little child pictured fot the family album (bottom). Pictures: Oksana Vasilishina, Sergey Kostryukov

She could not remember her name, and all efforts to discover her family ended in failure. The girl wouldn't speak to anyone although it was clear she could understand what people were saying.

Believing her to have been mentally challenged since birth, head doctor Alexander Bendera recalled how staff tried to coax her real name from her.

'We told her different female names and looked at her reaction,' he said. 'She got a bit more lively when she heard the name 'Lyuda' (short for Lyudmila). As we have found out now, we were correct, it turned out to be her real name. But we didn't know who was she and registered her with Neizvestnaya ('unknown') as her family name.'

One and a half years after being in care, she started to speak and her first three words were Lyuda, mama and babushka (grandmother). She explained she had run away from a hospital, but could not explain where this was.

Sergey Kostryukov, Lyudmila's uncle (top) and Natalia Dolgopolova, Lyudmila's deceased mother (bottom). Pictures: Sergey Kostryukov

Now a new hunt by volunteers using social media and other web resources has found out that she comes from the city of Birobidzhan in the Jewish Autonomous Region in the Far East of Russia, a distance of some 4,000 kilometres from Krasnoyarsk.

Three days after starting a campaign to reunite Lyudmila with her lost family, they received a call from the young woman's uncle, Sergey Kostryukov, 44. He saw the posting and 'recognised her face'.

He named her as Lyudmila Dolgopolova, and confirmed she had been 'disabled' since birth. She repeatedly ran away from home, but in 2007 escaped from the local hospital - and never came home. He explained the tragedy of how the family believed Lyudmila was dead.

Now a new hunt by volunteers using social media and other web resources has found out that she comes from the city of Birobidzhan in the Jewish Autonomous Region. Picture: Oksana Vasilishina

Her devoted mother Natalia Dolgopolova in 2008 was shown by police the burned corpse of a teenage girl and identified it as Lyudmila. Beset by grief, Natalia hanged herself soon afterwards. The grandmother that Lyudmila clearly remembers is also now dead. The uncle is now planning a trip to meet Lyudmila, hoping she will recognise him.

Still unclear is how Lyudmila made the trip across Siberia. But her uncle said that a mystery man had helped her flee the hospital. Social worker Elena Ladygina, who has cared for her, thinks Lyumdila did not come by plane, even though she was found at the airport.

Still unclear is how Lyudmila made the trip across Siberia and overcame the distance of some 4,000 kilometres from Birobidzhan to Krasnoyarsk. Picture: The Siberian Times

'Probably she came with truck drivers,' she said. 'Once I showed her a truck on the road and asked: 'Did you go by big cars?'

'She confirmed this. It seems someone took advantage of her state and led her out of the hospital, and then threw her away. And the most horrible thing is that the crime was committed when she was underage. I hope the police will sort it out.'

As nurse Valentina Ivanova said, Lyudmila is popular at the only home she has known for nine years. 'She's our favourite. Kind, easy,' she said. She's always happy to help when I ask. She can sweep floors, do the dishes.

'She loves planting flowers - tulips, roses - in our flowerbeds. She enjoys walking. Our mental hospital is on the bank of the Yenisei River. We have a great view.'