British Police are appealing for people who attended a fancy dress event at a skydiving centre the night before an Army cadet fell 13,000ft to his death, to hand over photos and video footage.
Humberside Police have launched a murder inquiry after they found the cord on the 20-year-old Stephen Hilder's main parachute had been deliberately severed as well as the strapping on his reserve chute.
Mr Hilder plunged to the ground in seconds as horrified onlookers watched from nearby Hibaldstow Airfield in North Lincolnshire on Friday afternoon.
A veteran of more than 200 jumps, he was taking part in a competition with seven other skydivers at last week's National Championships of the British Collegiate Parachute Association.
Students from across the country had travelled to the championships being held at the airfield near Brigg.
Det Supt Colin Andrews, from Humberside Police who is leading the investigation, said it was vital officers spoke to fellow skydivers at the centre who may have video footage or photos of the fancy dress party on Thursday night which may provide vital clues.
He said Mr Hilder was a popular skydiver with no known enemies and a motive for his murder remained a mystery. "He has a stable family background which makes the motive for this a mystery. "One thing we have to consider is that this was a random act and Stephen was in the wrong place at the wrong time."
Mr Hilder had successfully completed a jump on the Wednesday, he said, and had attended Thursday night's party. Mr Andrews added: "The parachute was purchased by Stephen and he was very safety conscious. It was stored in a room at the site and during the evening that store was locked.
"During the day people had access to it. We are trying to establish where the parachute was between Wednesday evening and up to the time of his death."
Officers are also liaising with the Army at the Defence Academy in Shrivenham near Wiltshire, where Mr Hilder was an officer cadet and undergraduate.
PA