An eight-year-old girl in Germany has been freed after her mother and grandparents allegedly kept her locked inside their home since she was 18 months old.

The girl, known only as Maria, was so underdeveloped that she could barely climb a flight of stairs or walk on uneven ground and had never attended kindergarten or school.

She was taken from the only world she ever knew on September 23 when authorities raided the grandparents’ property in the town of Attendorn, after concerns were raised by the girl’s father and a tip-off was given to police.

“She can’t have managed to get much of a glimpse of the outside world,” the prosecutor Patrick Baron von Grotthuss told local newspaper Sauerland Kurier.

A medical examination found no evidence of malnourishment or physical abuse, according to authorities, but the Kurier reported that she revealed during the examination that she “never seen a forest, been in a meadow or driven in a car” and documents stated she spent most of her time inside a locked room in the house.

The Times reported she was overwhelmed by the outside world.

Maria has been placed with a foster family while police investigate her mother and grandparents for their role in hiding her away.

Missing Maria

Maria’s parents were separated by the time she was born in December 2013, but the relationship was reportedly good enough that he attended her birth, the Kurier reported.

Contact continued until Maria was around six months old, when a note on his windshield from Maria’s mother told him that she was moving the pair to Italy.

He was provided with an address in Italy but his suspicions were raised when he saw Maria’s mother in Attendorn in September 2015.

The local youth welfare office investigated but was told by Maria’s parents that they had shifted to Italy so they sent letters to that Italian address.

Maria’s dad was sending letters and gifts too - but they all came back unopened.

He reportedly considered going there in person but thought he would not have been welcomed, later having a child with another woman and giving up hope of contacting Maria.

Authorities made repeated efforts to check the house over the years but were always refused access. When police became involved they had no search warrant and the grandparents refused to let them in, court documents sighted by the Kurier show.

It took a tip from a relative on the maternal side of the family to crack the case.

A relative told police that he had recently visited the Italian address where Maria and her mother were supposed to be staying, only to find that neither had ever lived there.

Police then received clearance to search the property on September 23 this year, finding Maria inside her improvised prison and launching an investigation into her mother and grandparents.

The public prosecutor’s office in Siegen is now investigating them on suspicion of deprivation of liberty and the abuse of wards, Bild reported.

Maria’s father found out about his daughter’s emancipation via a letter and said it was “a shock”. He has reportedly said he wants custody of the girl so he can show her the world and lead a “normal family life”.