A private jet pilot has allegedly accused Justin Bieber of boarding a plane while high on marijuana, according to a U.S. report. Editors at TMZ.com claim to have spoken to a pilot who recently took Bieber and his crew on an internal U.S. flight, and the unnamed aviator claims the star and his friends boarded the plane reeking of smoke which billowed from their van. The pilot alleges Bieber was "baked out of his mind" during the flight and was disorientated when crewmembers asked him to sign a credit card authorisation form, although the star did not light up while on board. The pilot compares the journey to Cheech and Chong's 1978 stoner movie Up in Smoke. A representative for Bieber has yet to comment on the report.