A man in his 30s, who was airlifted to hospital after an incident on Norfolk's Royal Estate, is in a 'critical' condition tonight.

Officers were called to Lower Lake, between the estate offices and Sandringham House, where the Queen and members of the Royal family spend Christmas, at around 1.30pm, following reports that a man had fallen into the water.

Norfolk police said in a statement: 'Emergency services have today been in attendance at an incident in Sandringham.

'Officers were called to the scene at around 1.30pm following reports of a man who is believed to have fallen into the Lower Lake area close to the B1440. It is understood that the male was riding a ride-on lawn mower at the time.

'The man was retrieved from the water and was taken to Addenbrooke's Hospital in Cambridge by air ambulance for treatment.

'He is currently described as being in a critical condition. Police and the Health and Safety Executive are carrying out a joint investigation into the incident. The male, who is aged in his 30s, is a worker on the estate.'

A spokesman for the East Anglian Air Ambulance said the man had been flown to Addenbrooke's with 'life threatening' injuries.