Police in Brazil believe that Greece's ambassador to the country was killed by his wife's lover under her orders in a house in the Rio area and have detained three suspects, authorities said Friday.

Kyriakos Amiridis, 59, was last seen Monday night, the police said in a statement. A burned body the police believe is the diplomat's was found inside his torched car in Rio.

Francoise, his Brazilian wife and the mother of their 10-year-old daughter, reported him missing Wednesday, Reuters reported.

On Friday, police investigator Evaristo Pontes Magalhaes said that 29-year-old police officer Sergio Gomes Moreira Filho had confessed to killing Amiridis, alleging self-defense.

Globo TV reported that investigators said they believed Françoise and Moreira had arranged the murder in advance.

Francoise has denied any role in the alleged plot. According to Magalhaes, Francoise said she couldn't stop Filho from killing her husband and insisted she was not at home at the time of the crime.

Rio de Janeiro police investigator Giniton Lages told The Associated Press that blood spots believed to be those of the ambassador were found on a sofa inside the home of the wife.

Another investigator said the ambassador and his wife fought three days before Christmas.

The Associated Press contributed to this report.