A mother has been arrested and accused of murdering her six-year-old son in Brazil in a sick medieval ritual to avoid giving custody to his dad.

The young boy was found dead with head injuries and sticks inserted into his mouth and anus and his body was covered in bruises and injuries, reported local media.

Sara Victoria, 26, was arrested for the murder of her son Thiago Junior Duarte in Salesopolis, Sao Paulo state, Brazil, on 8th October.

Victoria had reportedly argued with her partner, the child’s father – named as Thiago Alves da Silva Duarte, 38 – before taking the young boy into the woods and allegedly killing him in the ritual.

But Thiago Junior’s grandmother, Vandira Borges da Silva, age not reported, is said to have spoken to her daughter at the police station after her arrest.

She claims that her daughter denies having killed her son and has blamed the boy’s father for being involved in the crime.

The boy’s body was reportedly found covered in bruises and injuries, with the police report reportedly saying that the father had assaulted the young boy as well as the mother before she fled with little Thiago.

But neighbours quoted in local media claimed that Victoria laughed while her son begged for help.

The couple were reportedly in the process of separating and the father gave a statement at the police station after Victoria was arrested.

Local media speculated that she allegedly killed the boy to avoid giving custody to his father.

The dad’s lawyer, who has not been named, confirmed that they were in the process of separating, according to local media.

The dad, Thiago Alves da Silva Duarte, reportedly went to the house to pick up his son that evening while the mother was sleeping but she woke up and they began arguing.

The young boy’s corpse was found by the local fire department behind some trees at around 1.30am that night with a head injury, abrasions to his arms and sticks inserted into his mouth and anus in what local media called a “medieval ritual”.

Neighbours have reportedly organised a march through the city to pay tribute to the young boy.

The investigation is ongoing.