A father and son who hired hitmen to kill six members of their family so the former could start a new life with a mistress are on the run.

The pair are said to have fled from Brasilia, Brazil, after the assassins were seized by police on 14th January.

Thiago Gabriel Belchior de Oliveira, 30, paid BRL 100,000 (GBP 16,000) to the two killers, who wiped out his wife, three of their children, his mother, and his sister, say police.

His father – named as 54-year-old Marcos Antonio Lopes de Oliveira – is accused of being an accomplice in the murder plot.

Police believe the pair had planned to carjack his wife Elizamar Silva and kill her.

But when the hitmen and Belchior de Oliveira found his three children with her in the car, they killed them all.

Police believe her husband smothered one of his own children before the vehicle was torched on 12th January.

The badly burned bodies of Elizamar, 39, and her three children were found in the burnt-out car the following day.

Police named the children as Gabriel, seven, and six-year-old twins Rafael and Rafaela.

Then Belchior de Oliveira, his father, and the killers tortured his mother and sister for days to make them hand over the proceeds from a BRL-400,000 (GBP-64,000) property sale.

When that failed, they too were burned to death in a car belonging to Lopes de Oliveira.

Police in Unai found the torched car with two badly-burned bodies inside on 14th January.

Officers arrested the two hitmen on 17th January, reported local media, while the father and son who hired them have disappeared.

One of the men – Horacio Carlos Ferreira Barbosa, 49 – admitted that he and 55-year-old Gideon Batista de Menezes had received money to kill the family members.

In a further twist, police said Ferreira Barbosa had told them two other people participated in the crime.

One is allegedly Lopes de Oliveira’s lover and the other is her daughter. Both are also considered missing.

At the time of reporting, Batista de Menezes had been exercising his right to remain silent.

According to Ferreira Barbosa’s testimony, Belchior de Oliveira had lured Elizamar so she could be killed, but he had not realised their children were with her at the time.

The aim had been to make Elizamar transfer money from her bank account before killing her, but as the children were with her in the car, the plan changed.

Belchior de Oliveira, Lopes de Oliveira, and the two hitmen allegedly took the victims to Cristalina, where they suffocated all four before setting fire to the car.

Elizamar allegedly tried to fight back but was choked to death.

The other victims were named as 52-year-old Renata Juliene Belchior – who is Belchior de Oliveira’s mother – and his 25-year-old sister Gabriela Belchior de Oliveira.

Elizamar and Belchior de Oliveira had been married for 10 years.

Elizamar leaves behind a 24-year-old son and an 18-year-old daughter – from a previous relationship – who reported her disappearance to police.

Witnesses told police that Elizamar had fought with Belchior de Oliveira hours before her disappearance.

Police have also arrested a third suspect, identified as 34-year-old Fabricio Silva Canhedo.

He is accused of watching over Renata and Gabriela while they were being held captive.

The search for Belchior de Oliveira and his father continues.