A father-of-three arrived at Manchester Airport from a holiday in Greece, only to be arrested on the plane just minutes later for his involvement in violent scenes in Southport.
Thomas Whitehead, 53, was "seen in and amongst the large group" that gathered outside a mosque in the town on July 30, Liverpool Crown Court was told.
Prosecutor Rebecca Smith said his picture was circulated and he was arrested on August 13 at the airport while still on board the plane.
During questioning, the self-employed man told detectives that he had "been at a public house and noticed a large group gathering and went to see what was happening".