Police in southern Germany say a woman found by officers during an eviction may have been held captive by her mother for years.
The 26-year-old was found by chance in a locked room when officers entered a flat in the city of Rosenheim.
She was in a neglected state, a spokesman said.
Her 54-year-old mother threw herself down a stairwell in an apparent suicide attempt as police tried to enter the flat.
She was badly injured and taken to hospital, police said in a statement. The younger woman, who was described as "mentally disabled", was taken to a specialist hospital.
"We believe that this is the tenant's daughter, who was in a physically run-down state and who had lived in there for a long time, maybe even for years," police spokesman Stefan Sonntag told local news site rosenheim24.de (in German).
The investigation is focusing on the possibility of unlawful imprisonment, the statement said.
A neighbour, who was not named, told the news site he had lived next door since 2003 but had never seen the younger woman.