A woman has confessed to poisoning 10 dogs as a test run before allegedly murdering an elderly man with a toxic bean stew.

Ana Paula Veloso, described by Police Chief Halisson Ideiao as a "psychopath" and a serial killer, is accused of killing pensioner Neil Correa da Silva in Baixada Fluminense, Rio de Janeiro, Brazil, by serving him a poisoned bean stew.

Detectives suspect that Veloso was assisted in the murder by the victim's daughter, Michele Paiva da Silva, who allegedly paid for her to travel from Guarulhos to Rio to aid in the assassination.

Both Veloso and Paiva da Silva are currently in police custody and are suspected of involvement in three additional murders. Mr Halisson revealed: "She confesses that she killed 10 dogs with this poison, testing the method and the timing. She knew exactly how long, the dosage, and what would happen to the people who consumed what she offered."