Former patients of a knee surgeon who is believed to have died at Mawgan Porth while trying to save four children from the sea have paid tribute to him as a "hero".

Stuart Calder, 52, and two other adults were pulled unconscious from the water off Mawgan Porth beach in Newquay, Cornwall on Sunday afternoon and later pronounced dead.

While formal identification of the victims, whose deaths are not being treated as suspicious, is not expected until later today at the earliest, it is understood that the man from Leeds was Mr Calder.

He worked as an orthopaedic surgeon specialising in treating knee conditions at the Leeds Teaching Hospitals NHS Trust and The Yorkshire Knee Clinic.

Four teenage boys - two aged 18, one aged 16 and one aged 15 - were taken to hospital after the incident but were found to be "safe and well".

Patients and colleagues of Mr Calder's paid tribute online, with a tweet from the Orthopaedic Network saying his death was "a massive blow for orthopaedics".

A former patient of his wrote: "Shocked to hear of death of Stuart Calder. Reconstructed both my knees and was a credit to his profession."

Another woman described Mr Calder as "one of the best consultants I've ever worked with" and a "hero".

Mr Calder's mother Gillian told the Times: "My heart is broken, that's all I can say."

Gareth Horner, lifeboat operations manager, said he understood one of those who died had gone into the water to help the others in trouble.

Eric Hanson, a family friend of Mr Calder's said he would not be surprised if this was the case.

He told the Mail: "It's absolutely characteristic of him to put himself in danger to save others, especially children."

Lifeguards patrol the area between March and September only, but a spokeswoman for the RNLI said lifeboats "on call 24/7" can launch within 10 minutes all year round.

She confirmed a review of the beach's lifeguard cover during the autumn and winter holidays would be undertaken.