Police have resumed the hunt for clues following a collision between a helicopter and an aircraft which killed two pilots and two passengers over Buckinghamshire.
Police have yet to release any details of the victims, saying their priority was finding and informing the next-of-kin.
Superintendent Rebecca Mears of Thames Valley Police said air crash investigators and police were expected to be at the scene until at least Monday.
She said it was “too early to tell” what might have caused the crash.
(PA Graphics)
The collision occurred at 12.06pm close to, but not in, the Waddesdon Estate, the former country seat of the Rothschild banking dynasty.
Both aircraft are believed to have come from the Wycombe Air Park, which is about 20 miles from the crash site, and were carrying two passengers each.
The plane involved was a Cessna 152 built in 1982 and owned by Airways Aero Associations which is based at the Wycombe Air Park.
It had flown almost 14,000 hours as of May and had previously suffered substantial damage to its landing gear, propeller and engine following a crash at a Cornish airfield in 1993.
A forensic tent at the scene near Waddesdon (Aaron Chown/PA)
An archived report by the Air Accidents Investigation Branch (AAIB) shows the pilot admitted the accident was caused by his “misjudgment and lack of experience”.
AAIB investigators could be seen at the scene carrying what appeared to be wreckage debris in clear plastic bags.
Also at the site were fire investigators and police. Police tape marked the inner cordon which could be seen through the thick bushes that surround the area.
Waddesdon Manor said in a statement: “Lord Rothschild and his family extend their condolences to the families of all affected, and their thanks to the emergency services for their swift response and professionalism.”