Derek Brien after his Junior Manx Grand Prix win in 2007
Irish rider Derek Brien has been killed in an accident at the Isle of Man TT.
The county Meath man, 34, crashed on the first lap of Monday's opening Supersport event, which led to the race being halted.
Brien, a former Manx Grand Prix winner and a regular competitor on the Isle of Man, is the third rider to die at this year's TT.
Sidecar racer Bill Currie and his passenger Kevin Morgan were killed in a practice crash last Tuesday.
Monday's accident happened at the Gorselea section of the circuit.
Brien, from Bellewstown in county Meath, won the Junior event at the 2007 Manx Grand Prix on the Isle of Man.
The Irish rider was also a regular competitor at both the North West 200 and Ulster Grand Prix.
He also participated in the Irish Superbikes Championship, with his best performance a third placing in the Open 1000cc series in 2007.
Brien opted out of racing during the following season for financial reasons but returned to action in 2009.
Jim Parker, managing director, ACU Events described Brien as a "very talented road racer".
"Derek achieved a number of notable career highlights including his Manx Grand Prix victory. He will be sorely missed," said Mr Parker.