Brazilian police arrested a 17-year-old girl suspected of killing her mother after the older woman opposed her relationship with a young man three years older, authorities said.

After the teenager was arrested, she confessed while police were questioning her, Antonio Ricardo Nunes, the Civilian Police investigator in charge of the case, said at a press conference.

According to the police version, the girl killed her mother on May 25 in the Rio de Janeiro suburb of Cachambi but then went to the police to report Adriana Moura de Rocha Miranda, 43, as missing.

Their investigation led police to focus on the daughter as the prime suspect and to believe that her boyfriend, Daniel Duarte Peixoto, acted as an accomplice in the deed.

Police found the spot in a pasture where the couple had burned the woman's body then hidden it and also turned up security camera photos showing them buying ethanol at a nearby service station.

According to police, the girl decided to kill her mother because the latter opposed her romance with Peixoto and because she wanted to collect on her life insurance policy of 15,000 reais (about $7,500).

During one of the interrogation sessions, the accused admitted asphyxiating her mother while she slept.

"They confessed to the crime in just the fourth questioning session. First, they came here to report the disappearance," Nunes said, adding that the couple will be charged with premeditated murder and hiding a body.

When presented to the press, the teenager remained silent and her boyfriend said that he only hid the body and did not participate in the killing. EFE