A BODYBUILDER allegedly murdered his wife with the help of his mum after she discovered he was having a secret love affair.

Luiz Garnica, 38, and his mum, Elizabete Arrabaça, were arrested on suspicion of poisoning Larissa Rodrigues in Ribeirao Preto, Brazil on Tuesday.

Rodrigues had just learned of her husband’s affair when she died on March 22, according to the investigation.

She uncovered a shocking truth upon discovering intimate items in her spouse’s car, with whom she had shared 18 years of marriage, as shared by her cousin in a police statement.

The 37-year-old Pilates instructor was reportedly planning to divorce her husband after uncovering his dark secret.

But she died before she had the chance, after allegedly being slipped poison by her mother-in-law at the couple’s apartment.

Brazilian cops arrested Garnica and his mum after a toxicology test showed up with traces of chumbinho.

Chumbinho is a deadly pesticide which has been illegally commercialised as a household rat poison in Brazil.

On the day of Rodrigues’ death, Garnica claimed that he arrived home and called out to his wife who did not respond, according to the police.

He said that after searching for her in several rooms, he finally found her on the bathroom floor unconscious.

The bodybuilder and orthopaedic surgeon claimed he picked her up off the floor and carried her to the bed to carry out urgent emergency procedures.

When these proved unsuccessful, he called the emergency services.

Medics confirmed Rodrigues’ death at the scene and the case was immediately registered as a suspicious death.

Leading the investigation, Detective Fernando Bravo remarked, “Garnica’s involvement became clear when we saw the condition Larissa was in; she had already reached 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 has stated that Garnica 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 before her shocking death, 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 further revealed, “We located a witness who noted that the mother-in-law was seeking to purchase lead about two weeks prior to the incident, confirming our suspicions that she, along with her son, was involved in Larissa’s death.”

Arrabaça has denied all wrongdoing.

Garnica is believed to have gone on a cinema date with his lover hours before helping to end his wife’s life.

Police chief Fernando Bravo revealed that they had recieved a photo of Garnica with his mistress in a “public place,” from an anonymous source.

The photo led to Garnica admitting 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.

It is believed that Garnica’s love affair had been going on for around 18 months.

Garnica posted a gushing tribute to his late wife on social media, 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.”

This comes after a string of horror poisoning cases across Brazil over the past few months.

A woman accused of killing three relatives with an arsenic-laced Christmas cake was found dead in her jail cell in February.

Deise Moura dos Anjos, 42, was found lifeless in her cell at a women’s prison in Guaiba on the outskirts of the southern city of Porto Alegre.

The alleged cake killer was remanded in prison on January 6 on suspicion of three murders and three attempted murders.

She always maintained her innocence, despite police branding her a “serial killer” after her arrest.

Local cops had said that the evidence they had that she poisoned the deadly was “robust.”

Her mother-in-law, Zeli, baked the cake eaten by the relatives who fell ill – and it’s thought Deise contaminated it with arsenic-laced flour.

Zeli’s sister Maida Bernice Flores da Silva, 58, another sibling called Neuza Denize Silva Dos Anjos, 65 and Neuza’s daughter Tatiana Silvia Dos Santos, 43, all died within hours of eating the cake.