A bitter row broke out between a police officer, head teacher and a parent because his cycle mask was "frightening the children".
The cyclist had allegedly become "rude and abusive" when challenged by a female member of staff about the mask as he waited to collect his stepson outside Lynn Grove Academy in Gorleston-on-Sea, Norfolk.
She had reported him to the police after several parents "rang in" to complain, according to reports.
A heated dispute then broke out in front of a crowd of pupils as an officer repeatedly warned the dad about his "aggressive" behaviour and threatened to arrest him.
But the man accused the constable of trying to "intimidate" him and said the school had no right to tell him he could not wear the mask - which he kept on because he was cold.