THE daughter-in-law of a woman who baked a deadly Christmas cake for her family has reportedly been arrested by police on suspicion of murder and attempted murder.

Deise Moura is married to Diego, son of Zeli Dos Anjos who baked a tradition Brazilian dessert over the festive period which killed both of her sisters and her niece.

Zeli, 61, is still in hospital fighting for her life after the tragic family gathering near Porto Alegre in southern Brazil on December 23.

She is the only one of the three sisters to have survived what appears to be a poisoning after cops found arsenic in the blood of those who ate the cake.

Her niece Tatiana Denize Silva dos Anjos, 43, and sister Maida Berenice Flores da Silva, 58, passed away after eating the dessert when they suffered cardiac arrest.

Zeli’s daughter-in-law Deise was arrested at her home in Nova Santa Rita late on Sunday, MailOnline reports.

Torres police chief Marcus Vinicius Veloso reportedly confirmed to the outlet that the mum-of-one was held over a triple murder charge.

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

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

Deise allegedly baked the cake at Zeli’s home on December 23 before taking it to Maida’s apartment for the family celebration.

Cops seized ingredients including flour and dried fruits, as well as pesticide, from the property.

According to one of the investigators, the cake had an odd “spicy” and “peppery” flavour, but this didn’t stop the Brazilian family from eating it.

Whilst arsenic is a highly toxic substance without any smell or taste, the spiciness found is not common for sweet cakes.

Police previously announced that they had launched a homicide investigation, but weren’t ruling out the possibility that the Christmas tragedy was an accident.

Last week they said they were “not aware of any disputes within the family” but promised to keep an open mind.

Officials are still awaiting full results from lab tests after the horror incident.

Tatiana’s 10-year-old son Matheus, Zeli’s great nephew, was also taken to hospital.

He was only released last Friday.

Meanwhile Zeli’s husband Paulo is set to be exhumed as cops investigate his death by food poisoning some months ago.

Family members told MailOnline that both he and Zeli fell ill after eating mashed bananas they grew in their garden some months ago.

Zeli was reportedly taken to hospital while Paulo died within hours of being admitted.

His body is set to be exhumed on Thursday for further testing.

Deise’s husband Diego is reportedly 39, with the mum-of-one possibly also in her late 30s.