Police searching for a 15-year-old boy who went missing after swimming in a lake have found a body.

Testwood Lakes nature reserve, near Totton, Hampshire, was evacuated as police marine units began the search on Wednesday afternoon.

The boy’s family have been informed and formal identification has taken place. A file is being prepared for the coroner.

The incident happened on a day temperatures in Hampshire soared to 36C amid a red extreme heat warning.

Police, including marine teams, have been carrying out extensive searches at the 150-acre nature reserve.

In a statement, Testwood Lakes said it was “extremely concerned” to hear of the “serious incident”.

The reserve, owned by Southern Water and managed by Hampshire & Isle of Wight Wildlife Trust, remains closed with people urged to avoid the area.

It is the latest in a number of water deaths during this summer’s hot weather.

Police recovered the body of 22-year-old Brody Leach after he got into difficulty in the River Severn in the early hours of Friday morning.

A man died at a beach in Essex on Friday, while on Wednesday, a 50-year-old man was pronounced dead at Aberavon beach after getting into difficulty while swimming in the sea off the south coast of Wales.

Several people died during a previous hot spell in May, including a teenage girl in Warwickshire.

Meanwhile, up to 20 teenagers were rescued from choppy seas off the Lancashire coast.

HM Coastguard said the children were helped on Friday evening in Fleetwood after they got into difficulty in rough seas “a significant distance out from the sea wall”.