Concerned parents and students at a Melbourne Catholic school have boycotted mass after calling for their priest to resign over abuse allegations.

A group of parents at St Patrick's School in Mentone and St John Vianney's School in Parkdale have been demanding that parish priest Father John Walshe stand down.

The Catholic Archdiocese of Melbourne has accepted that an 18-year-old seminarian was sexually abused by Father Walshe in 1982. Credit:ABC News

The Catholic priest defended Cardinal George Pell at the Royal Commission into Institutional Responses to Child Sexual Abuse and has been accused of sexually abusing an 18-year-old seminarian in 1982.

He was in his early 20s at the time and had been recently ordained. He denied the abuse and said the incident was consensual.