"Dupasquier was involved in a multi-rider incident between Turns 9 and 10, with all the session Red Flagged afterwards," the announcement read.
"FIM Medical Intervention Vehicles arrived at the website immediately and the Swiss rider was attended to on track before being transferred by medical helicopter, in a stable condition, to Careggi Hospital in Florence.
"Despite the best attempts of circuit medical employees and all those subsequently attending to the rider, the hospital has announced that Dupasquier has unfortunately succumbed to his injuries."
His team, Prüstel GP, said on Facebook,"We're devastated, and now all of our thoughts are with Jason's family. You are going to be sorely missed and never forgotten, Jason."
Dupasquier was in his second season from the Moto3 World Championship. He was ranked 12th in the standings with 27 points.
Dupasquier started his career in Supermoto where he was a multiple-time Swiss National winner. He won the NEC Championship Moto3 name in 2016 before going to the Junior World Championship a year later.