A 16-year-old boy has died after getting into difficulty while swimming in a lake in Nottinghamshire.

Emergency services were called to Colwick Country Park when the boy went missing at 17:20 BST on Wednesday, Nottinghamshire Police said.

A police underwater search team and the fire service also responded, finding the boy’s body just before 20:00.

Ch Insp David Mather said: “This is a tragic discovery and our thoughts are with this boy’s family and friends at this incredibly difficult time.”

“While work is now under way to understand how the boy came into difficulty, I would like to take this opportunity to highlight this case as a reminder of the devastating consequences of entering open water,” Ch Insp Mather added.

“As in this tragic case, open water can have hidden dangers that can prove fatal and I would urge anyone who spends any time on or near open water to use this case as a devastating reminder of that.”

The boy’s death comes as parts of the UK are set to experience the hottest day of the year so far.

Police confirmed the boy’s death was not being treated as suspicious and said a file would be prepared for the coroner.

Group manager Tom Staples, of Nottinghamshire Fire and Rescue Service, said rescuers had worked tirelessly during the search.

He reinforced the message about the dangers of swimming in open water, and added: “We urge everyone to take care around lakes, rivers, and other natural bodies of water.”

Philip Starbuck, 38, told the BBC he had been fishing at the lake at the time the boy went under the water.

He said he had seen friends of the boy trying to find him.

“I heard a loud screaming,” he said. “I spoke to some of the kids there. They were in hysterics and tears.

“They said he had got into trouble about 20 metres out.

“As I got there, there were a couple of kids in the lake diving down trying to find him but [they had] no luck.

“It was just heartbreaking.”

Friends of the boy, who has not been named by authorities, went to the lake on Thursday to pay tribute.

They left flowers and balloons for the boy.

Malachai Pealt, 18, said: “We came to pay our respects because he always made everyone laugh. You could never have a bad day once you spoke to him.”

The country park is managed by Nottingham City Council.

City council executive member Sam Lux said: “This is an absolutely tragic incident and our hearts go out to the family and friends of the young person who has sadly died.

“As the current warm spell continues and as we approach the summer season we urge people to follow the guidance at Colwick park and other sites and not enter the water unless as part of properly supervised open water swimming sessions.”

Cat Wynne, of WholeHealth, which runs lifeguard-supervised swimming sessions at the park, said: “We were devastated to learn of the death of this young man in Colwick Lake.

“We are parents firstly, and our hearts go out to his family and friends.”

She said the boy’s death had happened outside of the business’s swim sessions.

“This incident sadly highlights the importance of the work of all organisations involved in teaching swimming and water safety and awareness,” she added.

“We send our sincere condolences to the family of the young man, and we are deeply saddened by this awful event.”