A helicopter and a light aircraft have collided in mid aid over a palatial estate, a development which has left as many three dead.
Aerial footage from above the site where a helicopter and plane collided in mid-air
Three people are feared dead after a light aircraft and a helicopter crashed in mid-air over Buckinghamshire this afternoon.
Wreckage from both aircraft fell from the sky after locals living near the historic and palatial Waddesdon estate heard a loud bang shortly after midday.
The pilot of the helicopter and its single passenger, as well as the pilot of the plane, are all feared to have died in the crash, which happened at around 1,000ft.
Pictures from the scene show splinters of metal from the helicopter littering the floor of the woodland along with parts of rotor-blades and fragments of the cockpit.
A local resident told MailOnline: 'My father heard a loud bang. He ran up to the scene. It was clear pretty quickly that no one has survived.'
The local added: 'My mother said a man, who I think was someone who had been out walking nearby, went running up to the manor to say there had been a crash. Everyone is now helping the emergency services.'
Both aircraft involved had taken off from Wycombe Air Park, which is 16 miles to the south east of the estate, and were flying at low altitude.
At least seven fire engines, including three search and rescue vehicles, rushed to the scene at around 12.06pm.
Police vehicles have now arrived at the crash site and officers have put up evidence tents in the woodland.
Rescuer workers had launched the fire brigade drone over the fallen wreckage to help in the search for survivors.
The helicopter involved in the collision was part of the fleet belonging to Heli Air, a company which provides helicopter training, flight experiences and can be chartered for private flights.
One of its bases is at Wycombe Air Park just a few miles away from the scene of the crash.
The company's Managing Director Richard Packe is due to give a statement later today.
Flight data shows a two-seater helicopter was flying at 1,025ft in the area at the time, but suddenly went of radar shortly after 12 noon.
Staff from the Waddesdon Estate, which is managed by a foundation set up by the eminent Rothschild family, helped direct emergency vehicles to the scene of the tragedy as police threw up a massive cordon around the area to preserve the scene.
The grand country manor house, which was used in the filming of The Crown and The Queen starring Helen Mirren, is understood to have been hosting a Christmas Market at the time of the crash.
Staff from the Air Accident Investigation Branch were also drafted into the area to begin an inquiry into what led to the mid-air collision.
Sources said that it was believed there were multiple casualties, believed to be fatalities.
Police at the scene of the incident
A spokesman for Thames Valley Police said: 'Officers are currently at the scene of an air accident near the village of Waddesdon near Aylesbury.
'The force is coordinating the response to the incident which was reported at 12.06pm today.
'The Air Accidents Investigation Branch has been informed and staff are en-route to the scene. Fire and ambulance services are also in attendance and preservation of life is first priority.
'In consequence of this incident it is expected that there will be some disruption to the road network around Waddesdon for the rest of the day.'
The spokesman later added: 'We're aware of a number of casualties following an incident this afternoon in Waddesdon, Aylesbury.
'There were a number of road closures following the incident, which have now been lifted. We will provide further updates when available.'
A spokesman for the AAIB said: 'The Air Accidents Investigation Branch is sending a team to investigate a mid-air collision involving an aircraft and a helicopter near Aylesbury.'
RAF Halton, which is around 10 miles away, said no military aircraft had been involved.
A spokesman said: 'We can confirm that neither of the aircraft concerned has a connection with either our air force nor the military, and this is as much as we know at this time.'