An air ambulance

Prince William's air ambulance in near-miss with drone

UK Airprox Board investigators said the Eurocopter 145, used by the East Anglian Air Ambulance, missed the remote-controlled machine "by chance".

The incident happened 1,900ft (579m) above London in August.

There had been "high risk" of a crash, "endangering the EC145 and its crew" over a busy area, theĀ reportĀ said.