An off-duty police officer punched a man and a 16-year-old girl in response to a bullying incident involving his son at a Bendigo primary school, a court has heard.

Keilor Downs Constable Jason Mooney went to the home of Adam John Rooney on August 21 last year to confront him over schoolyard bullying that occured between their two sons at a primary school in Kangaroo Flat, the Bendigo Advertiser reports.

Constable Jason Mooney leaves court. Credit:The Bendigo Advertiser

The pair began to fight and Mooney punched Mr Rooney twice, before punching Mr Rooney's daughter in the head, the Bendigo Magistrates Court heard on Wednesday.

Mr Mooney, who lives in Bendigo, told the court he had gone to the house to try to resolve the issue of Mr Rooney's 12-year-old son bullying his 10-year-old son.