The death of missing seven-year-old Conley Thompson, whose body has been found on a building site, is believed to have been accidental.
Conley vanished after playing with friends in Locke Park, a mile away from the site and about two miles away from his home in Barnsley, South Yorkshire.
Police said Conley had gone to play at about 6pm on Sunday and was due to return home around two hours later, but never turned up.
Today the body of the schoolboy was discovered at the site on Bank End Road in Worsbrough.
Police said Conley's family have been informed and that although formal identification was yet to take place, they believed the body to be Conley's.
It is understood officers are treating his death as a "tragic accident".
Detective Inspector Victoria Short, leading the investigation, said: "We deployed our full resources with officers searching throughout the night to find Conley and we are deeply saddened by this tragic development.
"While it is early in the investigation, the death is being treated as unexplained and a post-mortem examination will take place in due course.
"Our thoughts remain with Conley's family and friends at this very difficult time."
Detectives looking for the schoolboy cordoned off the building site today, as dozens of police had scoured the area for clues as to his whereabouts.
After news of the tragedy broke, people started to lay flowers and teddies next to the construction site where the youngster was found at about 8.30am.
Wayne Bolton, who was with his son, Finley, four, said the first he heard was the helicopter being used to search for the boy on Sunday night.
Mr Bolton said: "We are not friends with the family, but it's tragic what's happened and it just makes you appreciate what you have.
"I can't begin to imagine what that family are going through.
"It was such a tragic accident, hopefully, and we just want to show support for the family and to be fair the whole community has turned up. It's shocked everyone and everyone is in bits and luckily, in an area like this, everyone comes together and we all help each other."
Seven-year-old Evan Dunning was friends with Conley and was in the year above him at school.
He described Conley as "a bit naughty" and used to play football with him. When asked if he would miss Conley, Evan nodded.
Evan's mother, Cheryl Dunning, said the discovery of Conley's body was "sad, very sad". She added: "It makes it worse because he's the same age (as her son) and everyone knew him."
Kelsey Heeley, 17, who lives near the construction site, said: "I can't really put into words how people are feeling because you don't know.
"It's heartbreaking, because he's a young boy. It would be heartbreaking if it were anybody but he had his life to come."
There have been claims that children regularly play on the site where Conley was found.
Writing on Twitter, a user called Brett said he used to live near the area and added he "can't imagine what the family are going through".
He added: "I will say this about the spot where Conley Thompson was found, it is a dangerous place to play but kids do. I was knocked unconscious there."
The Rev Trevor Keightley, vicar at the nearby St Thomas' Church in Worsbrough, said: "We are all shocked and all our hearts go out to the family and our thoughts and prayers are with them at this time.
"Everyone's feeling it at the moment and everyone is very upset about it all.
"There was lots of people on Facebook and others going out to look for him, so people were very concerned for him."