Talented 21-year-old rider Ollie Bridewell died after a crash in the first free practice session at the British Superbike Championship at Mallory Park on Friday.
Bridewell, from Devizes in Wiltshire, suffered critical head and neck injuries when he came off his Team NB Suzuki at the Esses section of the Leicestershire circuit after completing two laps in the rain.
"Initial evidence shows that he lost control and fell from his machine making a heavy impact with the surface and then the Recticel "type A" protective barrier," said a statement from the Motorcycle Circuit Racing Control Board (MCRCB).
The session was stopped as Bridewell, who was in his second season in the series, was treated at trackside and then at the circuit medical centre by the BSB medical team where he died.
"The incident is being investigated by the MCRCB and the relevant authorities," the race organisers said in a statement on the BSB Web site (www.britishsuperbike.com).
All practice and qualifying sessions for the ninth round of the British Superbike championship were rescheduled for Saturday with the races taking place on Sunday.