James Rossiter has stepped down from the ByKolles privateer LMP1 squad for next month's Le Mans 24 Hours in order to undertake a Super GT test with Toyota.
The Japanese manufacturer is understood to have insisted on Rossiter's presence at a two-day test at the Sugo circuit over the Le Mans weekend on June 17/18.
It appears that the 33-year-old, who won the Super GT round at Autopolis earlier this month with the TOM'S team, had originally been given clearance by Toyota to race at Le Mans for the first time since 2013.
Rossiter revealed last month that a desire to go back to Le Mans for a third time was behind his participation in the opening two rounds of the World Endurance Championship aboard the ByKolles ENSO CLM-NISMO P1/01.
Toyota-contracted drivers Kazuki Nakajima, Yuji Kunimoto and Ryo Hirakawa, who all race the Japanese manufacturer's Lexus SC GT500 cars in Super GT, will miss the Sugo test to compete in French enduro.
Neither Rossiter nor ByKolles team boss Colin Kolles were available for comment.
It is expected that former Audi LMP1 driver Marco Bonanomi will take Rossiter's place alongside Oliver Webb and Dominik Kraihamer.
The Italian, who finished third in the 24 Hours in 2012, tested for the German-based team at Spa last week and is likely to be confirmed ahead of this weekend's official pre-race test at Le Mans.