Promising British racer Harry Stafford has announced he has been forced to retire from the sport at just 21 years-old after doctors informed him he could not risk another big bang to the head.

Stafford was hospitalised with a serious head injury in 2013 and then came back to European Superstock 600 action last year only to crash heavily again at Imola. Medics have advised him that he cannot risk further brain damage.

“As it is now 2015 I thought I should tell you all that through the repeat head injuries doctors have advised that I retire from the sport,” Stafford wrote on Twitter.

“With risk of more brain damage it is the right thing to do. I’m very upset that my career has ended but I will stay involved somehow. Thank you all for the support over the years of my racing.”