Thiruvananthapuram: Mysterious death of a 15-year-old girl at Nedumangadu in Kerala's Thiruvananthapuram district has taken a new twist on Saturday with the arrest of her mother and neighbour.

The case started with a missing complaint filed by the class X student's grandmother two weeks ago. The cops started investigation and tracked down the girl's mother Manjusha and her lover Aneesh in Tamil Nadu. The duo had fled Kerala after the girl went missing, raising suspicion of the police.

During the interrogation, the duo revealed that they were having an affair and the girl had a fight with her mother following which she hanged herself in the house.

The mother and her lover, who is also a neighbour, panicked and took the body on a motorcycle to a nearby well in a deserted area. They tied the body to a boulder and dumped it in the well before fleeing the state.

The police suspect that the duo murdered the girl and dumped the body and arrested Manjusha and Aneesh. The body was found in highly decomposed stage.

The girl used to live with Manjusha at a rented home in Nedumangadu. According to police, Manjusha, who has been living separately from her husband, started an affair with the neighbour and this had enraged the girl.

Cops are investigating whether the duo's story is correct or the girl was murdered by the mother and lover.