A mid-air collision between a small plane and a helicopter killed three Britons and one Vietnamese national, police have said.
Officers said the four victims were all men, and have since confirmed three were British, and one was Vietnamese.
All four bodies have been recovered from the crash scene near Waddesdon in Buckinghamshire and post-mortem examinations were due to begin on Sunday.
Officers, military personnel and air accident experts were still at the wreckage spot, 48 hours after Friday afternoon’s crash.
Superintendent Rebecca Mears said: “Our thoughts remain with the families of the men who have tragically lost their lives.
“Specially-trained family liaison officers are continuing to offer their support to the families of the victims affected, three of whom we understand to be British nationals, one of whom is a Vietnamese national.
“Work will today focus on removing the aircraft from the scene which will be done with specialist support.”
Three of the families visited the site on Saturday.
Formal identification of the four men has not yet happened, but one of the victims was named by former colleagues on Saturday as Captain Mike Green.
He was a senior instructor with Helicopter Services, which operates from Wycombe Air Field, where both aircraft had come from on Friday afternoon.
A statement posted on the company’s Facebook page read: “We have received many messages of support and kind words about our friend who, as a senior instructor and examiner, helped and mentored so many pilots throughout the industry during his distinguished career.
“It was an honour to work with you. Captain Green, you will be greatly missed.”
The firm also confirmed he was with a student at the time, who also died.
Captain Phil Croucher, his friend, told Sky News: “I have known him for 20 odd years. We were both in the Army, we worked together.
“He was an ultra nice chap, very professional, would go out of his way to help people get on in their careers.
“He will be fondly remembered by everyone who knew him.”
The crash happened around 12.06pm on Friday, 17 November, between a helicopter and a two-seater Cessna 152 built in 1982.