Documentarian Eduardo Coutinho has been stabbed to death.
Police say the 80-year-old - whose films include Master - A Copacobana Building and Playing - was found dead in his apartment in Lagoa, south Rio and his wife Maria das Dores, 62, was also reported to be injured and is currently being treated in hospital for stab wounds.
The filmmaker's son Daniel, who was also admitted to hospital for treatment to stab wounds, has been arrested in connection with the alleged attack.
In a press conference, a police investigator said the director's son - who Brazilian media outlets say suffers from mental health issues - knocked on a neighbour's door after the attack saying he had "liberated his father".
Director of Rio's homicide departmetn Rivaldo Barbosa said: "He committed these atrocities and knocked on the neighbour's door, not making sense, not saying the right words."
