Police hunting Rory Blackhall's killer have found the corpse of an adult near to where the 11-year-old disappeared.
The body was found after police officers broke into the house
Officers are still searching the house in Livingston, near Edinburgh, where the adult body was discovered.
It is thought a man aged around 40 was living alone in the house, in the Camps Rigg area of the town.
Rory's body was recovered from woodland a week ago, and police said on Saturday they urgently wanted to speak to a man in his late thirties over the killing.
Lothian and Borders Police said a post-mortem examination and formal identification would take place on Monday.
The force said they were focusing their investigation on an "unusual" man who was spotted in the area of Livingston where the schoolboy was last seen.
The investigation into Rory's murder was launched a week ago
He was described as 38 to 40 years old, 5ft 8in tall, with a gaunt appearance and a pointed nose with light or grey stubble on his chin.
The man was wearing a black bomber jacket zipped up to the neck, black jeans and black boots or shoes.
Following the appeal, police received 300 calls from the public.
A forensic team began their inquiries at about 1200 BST on Sunday and an area near the house was cordoned off. They later confirmed the discovery of a body.
BBC Scotland correspondent Colin Blane said the house search was probably a result of information from the public.
Rory's body was discovered three days after he failed to turn up at school.
A post mortem examination revealed that he had been asphyxiated.
The boy's school, the woodland where his body was discovered, and the Camps Rigg house the police are searching are all within two miles of each other.
Detectives have launched a text messaging service on 07717 997 885 to encourage people to come forward with information.
The number allows the public to send in text messages as well as pictures and video clips.