Kochi | The investigation into the deaths of a six-year-old girl and her father in Elamakkara was intensified after an autopsy report revealed the child had been sexually assaulted prior to her death in January, police said on Sunday.

On January 16, the girl was allegedly poisoned before her father died by suicide at the rented house here.

Police officials said the autopsy report revealed that the deceased child was allegedly sexually assaulted for the past one year.

The child's mother has told investigators that the family was unaware of any such incident.

According to police, she told them there was a quarrel over a financial matter with her husband on the day the father and daughter were found dead.

An officer at the Elamakkara police station said the statements of relatives and people close to the family would be recorded soon.

The police will also speak to the teachers of the educational institution where the child was studying, the officer said.

The police have already begun a probe based on CCTV footage to check whether any persons had reached the house on the day the father and daughter were found dead, officials said.

Following the autopsy report, police have included the Protection of Children from Sexual Offences (POCSO) Act in the case, which was earlier registered as an unnatural death, the officer said.