“Dupasquier was involved in an incident involving multiple riders between turns 9 and 10, with the red flag session following,” the statement said.
“The FIM medical intervention vehicles arrived immediately on the site and the Swiss rider was taken care of on the track before being transferred by medical helicopter, in stable condition, to the Careggi hospital in Florence.
“Despite the best efforts of the medical staff of the circuit and of all those who subsequently took care of the Swiss rider, the hospital announced that Dupasquier unfortunately succumbed to his injuries.”
His team, Prüstel GP, said on Facebook: “We are devastated, and right now all our thoughts are with Jason’s family. We will miss you dearly and never forget you, Jason.”
MotoGP added on Twitter: “On behalf of the entire MotoGP family, we send our love to their team, family and loved ones. We will miss you very much, Jason. Ride in peace.”
Dupasquier was in his second season in the Moto3 World Championship. He was ranked 12th in the standings with 27 points.
Dupasquier began his career in Supermoto where he was several times Swiss national champion. He won the NEC Championship Moto3 title in 2016 before advancing to the Junior World Championship a year later.