A woman who promised her lover sex as a reward for killing her own seven-year-old son has finally been arrested four years after she went on the run.

Alexandra Moura da Silva, 32, was arrested in the town of Maribondo in the Brazilian state of Alagoas on Wednesday, 20th October.

A court had previously found her guilty of the murder of her own seven-year-old son, Carlos Henrique Moura, in the city of Camacari in the Brazilian state of Bahia in January 2015.

She is believed to have promised her lover, Jose Nilton Pereira da Silva, a night of sex as a reward for her son’s death.

Pereira da Silva was arrested a year after the crime and confessed to drowning the youngster in a stream, naming Moura da Silva as the instigator of the killing.

The police believe the woman ordered her son’s murder because she was afraid he would tell his maternal grandmother, who was raising him, that she was dealing drugs and was planning to participate in a bank robbery.

After the boy’s body was found three days after he had been reported missing, Moura da Silva attended his funeral and even fainted during his burial where she had to be supported by her partner.

However, she quickly turned from a grieving parent into a suspect after the police noted that the stream in which the boy was found was too shallow for him to have drowned of his own accord.

She was arrested two months later, but was released after her provisional 30-day custody period ended, after which she went on the run.

At the time of reporting, she was due to be transferred to an unnamed prison in the state of Bahia to serve her sentence, whose length was not reported.