Bodybuilder allegedly killed his wife with rat poison - with the help of his mum - after she found sex toys and discovered his affair

38-year-old Luiz Garnica was supposedly helped in his crime by his mum, Elizabete Arrabaça. They were both arrested on suspicion of poisoning Larissa Rodrigues, aged 37, in Ribeirao Preto, Brazil on Tuesday, (May 6).

Rodrigues died on Saturday March 22, shortly after she learned that her husband of 18 years had been having an affair, according to an investigation by local police. She discovered he had been unfaithful when she found sex toys in his car, her cousin told the police.

Rodrigues, who was a pilates instructor, was reportedly planning to divorce her husband when she was killed. She was allegedly given poison by her mother-in-law at the apartment she shared with Garnica.

He claimed he had returned home and found her dead. A toxicology test was carried out on her body, however, which revealed traces of chumbinho. Chumbinho is a deadly pesticide which has been illegally commercialised as a household rat poison in Brazil. Both Garnica and his mum were then arrested.

When interviewed Garnica, who is also an orthopaedic surgeon, told police that on the day his wife died he arrived home and called out to her but she did not respond. He then claimed that he searched several rooms in the apartment before he finally found her on the bathroom floor unconscious.

The bodybuilder claimed he picked her up off the floor and carried her to their bed to give her emergency first aid. When this proved unsuccessful, he called the emergency services.

Medics attended, but Rodrigues could not be saved and her death was confirmed at the scene. The case was immediately registered as a suspicious death.

Head of the investigation Detective Fernando Bravo said: "His [Garnica's] involvement was quite evident to us by the way he found Larissa, she was already in rigor mortis. And he tried to clean the apartment as if he was trying to destroy the evidence for the technical expertise."

Garnica's lawyer said his client is innocent. Garnica's mum was reportedly the last person to see Rodrigues alive the day before she died.

The police claim Arrabaça called a friend to ask about the alleged poison, according to Globo. A representative from the investigation said: "She even called a friend who is a farmer to find out if she had this substance on her farm. When her friend said no, she asked for a recommendation of where to buy it, but none were provided or recommended."

They added: "We managed to find a witness who reported that the mother-in-law was looking for lead to buy, approximately 15 days before the death, so this gave us certainty that she, together with her son, killed Larissa."

Arrabaça has denied all wrongdoing. Garnica is believed to have gone on a cinema date with his lover, who has not been named, just hours before he and his mum killed his wife. It is believed the two had been having an affair for around 18 months.

Garnica posted a tribute to his late wife on social media after her death, writing: “I love you, wherever you are. Know that you have made me the dearest, happiest and most loved man in the world and I want to always be your best friend, boyfriend, husband, companion, the love of your whole life, just as you are of mine.”

Police chief Fernando Bravo also said the force had recieved a photo of Garnica with his mistress in a “public place," from an anonymous source. After being confronted with the photo Garnica admitted to police that he had been cheating on his wife and had spent the night with his unnamed lover on the night his wife is thought to have died.