Fincham was involved in a crash with Jim Walker. Whilst Walker was largely unharmed Fincham sadly succumbed to his injury.
A statement released on the BSB website read:
Hickman reigns in Race 2
The management of Thruxton circuit and MSVR have to report that, following a two-machine motorcycle accident during a race for the Pirelli National Superstock 1000 Championship, a support race to this weekend’s round of the MCE British Superbike Championship (August 4/5/6 2017), the rider of bike number 903, Mark Fincham suffered serious injuries.
"The race was immediately stopped and the riders involved were treated immediately trackside by the BSB Medical Team before being transferred to the circuit medical centre.
"It is with great regret that we have to announce that Mark Fincham succumbed to his injuries while undergoing treatment. Jim Walker, number 90 was unhurt.
"MSVR and the staff at Thruxton circuit, are now working with the Coroner, Police and the Motor Cycle Circuit Racing Control Board in order to investigate the full circumstances of this tragic accident."
The True Heroes Racing team are unique in the sense that they are totally made up of injured ex-servicemen.
Fincham was an ex-marine who had his left leg amputated.
The team was set up in 2012 and uses modified bikes to allow their riders to race.
Hickman benefits from Brookes mistake to win Race 2
Josh Brookes takes Race 1 in Thruxton