Isle of Man TT newcomer Adam Lyon has died following an incident in Monday's Supersport race.
The incident occurred on the lap three of the four-lap Supersport race around the 28th milestone at Casey's, with organiser the ACU confirming 26-year-old Lyon had lost his life in a statement on Monday afternoon.
Lyon, from Helensborough in Scotland, was making his TT debut this year and already managed a best lap of 123.443mph of the 37.75-mile circuit during Friday's Superbike session.
He was on fine form in the Supersport race, lapping at 122.636mph from a standing start before his incident.
A podium winner in the National Superstock 600 series in 2010, Lyon impressed in last year's Ulster Grand Prix where, as a newcomer, he finished 11th in the Supersport race.
A statement from the ACU read: "ACU Events Ltd regrets to confirm that Adam Lyon, 26, from Helensborough in Scotland was killed in an incident during the Supersport 1 Race today at the Isle of Man TT races.
"The accident occurred at Casey's, just after the 28th mile of the course, on the third lap of the race.
"Adam was a newcomer to the TT this year. He qualified in 24th place for today's race with a fastest lap of 122.261mph, which he improved to 122.636mph on the opening lap of today's race.
"His fastest lap of the TT course - 123.443mph - was in Friday's Superbike qualifying session. Adam lapped at 122.499mph as a newcomer at the Ulster Grand Prix in 2017, finishing 11th in the second Supersport race.
"ACU Events Ltd wishes to pass on their deepest sympathy to Adam's family and friends."
Lyon is the second rider to have died during the 2018 event, after Manxman Dan Kneen was killed in an incident at Churchtown in Wednesday's practice.
Steve Mercer was seriously injured in a collision with a course car on its way to the Kneen incident, but is now said to be in a stable condition in hospital in Liverpool following pelvic and leg surgery.
The Supersport race ran to its four-lap distance, with Michael Dunlop taking his second win of the week with a new class lap record of 129.197mph ahead of Dean Harrison and Peter Hickman.