Police made the horrific discovery over the weekend.
The bodies of a missing three-year-old and his father were found in Portugal on Sunday.
Police found the charred body of the toddler in a burnt-out car, while his father's body was found nearby with a gunshot wound to the head.
The remains were discovered in a rural area around 100km from Lisbon, a week after the boy's mother allegedly reported him missing.
Authorities said they believe the deaths to have been a murder-suicide.
Portuguese newspaper Jornal de Noticias reports the tot's mother, a British stylist, and the boy's father, a German architect, split up earlier this year, but both stayed living in Portugal.
The man picked up the child from his mother's home last week and never returned, the publication alleges.
A police spokesman in Grandola said the case is being handled by Portugal's criminal investigation police.
The British embassy in Lisbon
told Reuters it was "supporting the family of a British-German dual national child who has sadly died in Portugal" and that consular staff had been in regular contact with both the child's family and local authorities.
