Brazilian cops reveal long-standing family feud in Christmas cake arsenic poisoning case as daughter-in-law of woman who baked dish that killed three is arrested on suspicion of murder

Detectives investigating a Christmas cake food poisoning that killed three members of the same family are expected to uncover a long-standing dispute between the woman who baked it and her daughter-in-law, who was arrested yesterday.

Deise Moura was detained by police yesterday at the home she shares with her husband Diego in the southern Brazilian state of Rio Grande do Sul, with police confirming that a female suspect had been arrested on suspicion of triple murder and attempted murder.

Deise’s mother-in-law Zeli Dos Anjos made the traditional festive treat that killed both her two sisters and her niece during a family Christmas celebration in Torres near Porto Alegre in southern Brazil on December 23.

Mother-of-one Zeli is still in hospital fighting for her life, while her two sisters Maida da Silva, 58, and Neuza Dos Anjos, 65, both died along with Neuza’s daughter Tatiana Dos Santos, 43.

They lost their lives within hours of eating the cake, and traces of deadly arsenic were found in their bodies, authorities later revealed.

Tatiana’s 10-year-old son Matheus, Zeli’s second cousin, was treated in hospital and only released on Friday, while Maida’s husband Jefferson was also treated, but Neuza’s husband Joao did not eat any cake and was unaffected.

Police are delving deeper into what they believe is behind the horror poisoning, with reports from Brazil suggesting the suspect and Zeli have fallen out in the past in a dispute reportedly linked to what happened next.

It comes after MailOnline revealed Zeli’s first husband, Paulo Luis, 68, died after eating a banana that was contaminated. Officials will exhume his body from its final resting place next Thursday as part of their investigation.

Zeli dos Anjos (photo) prepared the traditional festive treat ‘Bolo de Natal’ for a coffee afternoon with the whole family

In the photo: the Christmas cake that was consumed by the guests on December 23

The dramatic development of Deise’s arrest was shared exclusively with MailOnline by Torres police chief Marcus Vinicius Veloso, who said the mother of one was arrested late on Sunday at her home in Nova Santa Rita.

He said: “The woman was arrested for triple murder and triple attempted murder.

“She was first taken to a police station in Canoas, then to the Torres police station and is now in the women’s prison in the city, at this time we cannot say anything else.”

It was at Paulo and Zeli’s seaside estate where she made the cake on December 23, which she took to Maida’s apartment for the party, and at the house police seized ingredients including dried fruit and flour, as well as pesticides .

Last week, police said they are “not aware of any disputes within the family” but are open to hearing the results of laboratory tests coming in each day. Preliminary reports indicated that there was arsenic in the blood of the victims.

Investigative sources confirmed that Paulo’s body would be exhumed next Thursday for further analysis as none was taken after doctors at Torres Hospital ruled he had died of food poisoning.

Relatives have told MailOnline that he and Zeli suddenly fell ill after eating some mashed bananas grown from a plant in their garden, which may have become contaminated after floods swept through the region in May.

At the time, Zeli was also taken to hospital but recovered while Paulo died within hours of admission.

The group of seven at the Christmas party complained that the cake they baked tasted “bitter and peppery.” Within minutes they were all vomiting and a fleet of ambulances was called to take them to hospital.

Maida, a retired teacher, was the first to die on Christmas Eve, while Neuza died a few hours later, followed by her daughter Tatiana.

Deise was initially taken to a police station in Canoas, then to Torres Police Station and is now in the city’s women’s prison

The woman was arrested for triple murder and triple attempted murder

The mother of one was arrested late Sunday at her home in Nova Santa Rita

10-year-old Matheus Marques da Silva survived eating the poisoned cake with Father Leonir Alves in hospital in Torres, Brazil

Several members of the family died after eating the cake

Neuza Denize Silva dos Anjo, 65, was rushed to hospital in critical condition before dying the next day

Zeli’s 10-year-old grandnephew Matheus, Tatiana’s son, also fell ill and spent a week in intensive care before being transferred to a children’s ward from the Senhora dos Navegantes hospital in Torres on Friday evening.

Paulo’s brother Joao – married to Neuza – didn’t eat any cake, but Maida’s husband Jefferson had a few bites and also got sick, but didn’t have to stay in the hospital.

Just days ago, Jefferson’s sister Isabel Moraes, 54, told MailOnline exclusively that she believed someone with a “grudge” was responsible for attacking the family, describing the tragedy as “strange”.

When contacted by MailOnline to ask for her reaction to the arrest, she said: ‘The whole family is shocked. We just don’t know what to say, someone so close to us, we could never have imagined that.’