Air Accidents Investigation Branch
The Argentinian football player was killed in the crash on January 21, 2019.
The spill damaged equipment, producing an electrical burning smell and smoke, an accident report revealed.
The Air Accidents Investigation Branch is trying to establish what happened to the aircraft.
The aircraft was discovered on Sunday on the seafloor of the English Channel.
The Premier League footballer is presumed dead after the crash last month.
The privately funded search is being carried out behalf of the footballer’s family.
Flowers are being left near where the helicopter used by Vichai Srivaddhanaprabha crashed in flames.
The cause remains unclear.
Four people have died in a mid-air collision between a light aircraft and a helicopter near Aylesbury, Buckinghamshire, police
The scene is being investigated.