Hillarys police boss Alex Ryan said the situation escalated after the offender began abusing the umpire of a five-a-side indoor match at Craigie Leisure Centre on April 19.
He punched a fellow spectator in the stomach when he attempted to intervene.
‘A spectator approached the referee and said ‘you are the worst referee I have ever seen’,’ Senior Sergeant Ryan said.
‘The victim stepped in between the two and said ‘you can’t say that, you need to leave’.
‘The person of interest then punched him in the stomach.’
He said the matter had been referred to the inquiry team, which would continue to investigate.