Woman arrested for arsenic poisoning on Christmas cake ‘laced her mother-in-law’s flour’ before serving tainted dish to family that left three dead, Brazilian police suspect as they reveal couple’s 20-year feud

Brazilian police have revealed that the woman arrested over alleged Christmas cake poisoning had rowed with her family for years before three of them were killed by the arsenic-infused dessert.

Deise Moura, the daughter-in-law of one of the women who was poisoned but survived, was arrested yesterday at her home in Rio Grande do Sul on suspicion of triple murder and attempted murder.

Her mother-in-law Zeli Dos Anjos made the traditional festive treat that left three members of her family dead during a Christmas celebration in the southern city of Torres 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. Police Chief Marcus Vinicius Veloso said today that the flour found in Zeli’s home contained large amounts of arsenic.

“We suspect that the arrested person entered Zeli’s house and then contaminated the flour,” the investigating officer revealed at a press conference today.

Police and forensic officers confirmed that ‘elevated levels’ of arsenic had been found in the cake and in the blood and urine of those who had died, as well as those who survived.

Veloso added that other substances were found during searches of the suspect’s home in Nova Santa Rita, but he said tests and investigations were still ongoing and he could not comment further.

Police said the “disagreements” between the suspect and Zeli dated back nearly two decades, but declined to elaborate on what exactly they were, other than to say that “further elements would be released in due course.”

When asked about the family circumstances, Veloso said: “We knew that there had been minor disagreements between the suspect and elements of the family for years.

‘At first glance, everyone present at the party was close and harmonious, but as we expanded our investigation, we found motives that were likely behind this poisoning.

Police have also confirmed that they plan to exhume the body of Zeli’s husband Paulo, who died of “food poisoning” last September, to determine whether there were traces of arsenic in his body.

Veloso added: “We have the evidence, very strong and robust evidence that it was her behind this crime, and we have the reasons, but we cannot go into details yet.”

According to Marguet Mittman, director of the General Institute of Expertise (IGP), the source of the contamination was the flour used to make the cake consumed by the victims.

She told the press conference: ‘Very high concentrations of arsenic were found in the three victims. So high that they are poisonous and deadly.

‘To give you an idea: 35 micrograms is enough to cause death. In one of the victims the concentration was 350 times higher.’

She added that 89 samples had been collected from the home of the woman who made the cake, and only the sample, from flour, showed high arsenic concentrations.

Brazil’s Ministry of Justice today confirmed to MailOnline that an arrest warrant has been issued for Deise ‘on suspicion of committing a triple murder, with a futile motive and the use of poison, and three counts of attempted murder, with double aggravation. ‘

The ministry’s statement added that “the suspect will have a custody hearing on Monday afternoon.”

Police are said to have first started investigating Deise after an apparent argument with a family member at the victims’ funeral last month.

Deise is said to have placed a ‘set of rosary beads and a rose’ in the hands of Maida and Tatiana as they lay in their coffins at the cemetery, a gesture that led to an extraordinary outburst from an angry family member who, according to a source, shouted to MailOnline: ‘ Why are you here? You didn’t like any of them. Everyone knows.’

The source added, “Diego and Deise have been keeping separate from the rest of the family for the past few months. They didn’t really participate much. There was tension.’

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 digging deeper into what they believe is behind the horror poisoning, with reports from Brazil suggesting the suspect and Zeli have fought 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.

It was at Zeli’s seaside house that she made the cake on December 23, which she took to Maida’s apartment for the party, and from 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.

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.’