Police have suspended a two-day search for a missing swimmer who vanished during a night swim in the River Mersey.
Haydn Griffiths, 23, was last seen swimming with a friend towards offshore windmills by Derby Pool, New Brighton, at 10.30pm on Tuesday.
His family believe that the tide changed and he struggled to make it back to shore.
Haydn’s sister Megan pleaded with volunteers to keep up the search for her “incredible baby brother” who she hopes is still fighting to stay alive in the open water.
She wrote on Facebook: “This is the most important search in the whole wide world as my incredible baby brother is out there. He is the strongest human I’ve ever met and I know he’s out there fighting.
“The coast guard has been amazing and searching all night, helicopters, boats, drones.”
She added: “I understand that he may have tried to swim out the offshore wind turbines as the tide changed and he couldn’t swim back to shore.
“Anyone who knows Haydn knows how incredibly strong he is and despite the amount of hours he’s been missing, he’ll be fighting somewhere.”
After suspending the search, a spokesperson for the Maritime and Coastguard Agency said: “We have carried out an extensive search across the area and the missing person has – sadly - not been found. The search is now being suspended.
“Our thoughts and those of all our coastguard colleagues are with the family and friends of the missing man.”
Volunteers and lifeboats had been searching the Burbo Bank Offshore Wind Farm.
A Merseyside Police spokesman said: “Haydn was last seen in the water at the Derby Pool, New Brighton, wearing dark coloured swimming shorts attempting to swim towards the windmills in the area.
“An extensive search of the river was carried out last night and today by the Maritime and Coastguard Agency but Haydn was not found and the search has now been suspended.”
Haydn was described by police as being white, 6ft 1in tall, of athletic build with short blonde hair and blue eyes.
In Essex searches for a swimmer reported missing in the sea close to Clacton Pier were also scaled down, police have said.
Five people were pulled from the water and taken to hospital on Tuesday but a 21-year-old man was still unaccounted for more than 24 hours on.
The search came after the body of schoolboy Brian Sasu was pulled out of the River Thames as Brits looked to cool down during a record heatwave at the start of the week.
The 14-year-old went swimming with friends at Tagg’s Island in Hampton after his school closed early during Monday’s scorching 37C heatwave.
He disappeared under the water close to a bridge with friends and locals launching a desperate search to find him.
A 16-year-old boy died on Tuesday after getting into difficulty in Bray Lake, near Maidenhead, in Berkshire.
Robert Hattersley, 13, of Crawcrook, died following an incident in the River Tyne near Ovingham in Northumberland on Sunday, while the body of a 50-year-old man was recovered from Ardsley Reservoir, between Leeds and Wakefield, on Sunday.
A 16-year-old boy died after he was seen struggling in the water at Salford Quays, Greater Manchester, on Saturday.