A worker from the royal estate at Sandringham in Norfolk is fighting for his life after he became trapped underwater in a lake.
The man, believed to be in his 30s, was pulled from Lower Lake in the grounds of the Queen's Norfolk home on Monday afternoon.
It is understood he had become trapped beneath a ride-on lawnmower. Police and colleagues performed emergency resuscitation until paramedics arrived.
He was taken to Addenbrooke's Hospital in Cambridge where he is critically ill. Police and the Health and Safety Executive are investigating.
Click below to watch a report from ITV News Anglia's Russell Hookey at Sandringham