The US military helicopter which crashed killing all four people on board yesterday evening (Tuesday) had earlier been training at RAF Holbeach.
Police are still on the scene at Cley on the north Norfolk coast, leading an investigation on behalf of the coroner.
Also there are officials from the Ministry of Defence and the US Air Force as investigators probe a crash site the area of a football pitch.
A strict cordon remains in place around the site, a nature reserve, where a significant number of bullets from the crashed aircraft are scattered across the area.
Two USAF Pave Hawk HH60 helicopters were involved in the training. After one crashed at around 7pm, the second landed to offer assistance.
Speaking from the scene today, Chief Supt Bob Scully said: “Police continue to work with various partner agencies to piece together the exact circumstances concerning the crash.
“It remains a challenging, lengthy process due to the difficult terrain and the size of the area needed to be assessed. This will remain a police-led operation until such time the coroner is satisfied that the circumstances surrounding the deaths of the four occupants of the helicopter are non suspicious.”