Masks are currently required to be worn at all public indoor setting across Perth and the Peel, South West, Wheatbelt and Great Southern regions.

Five people were found to not be wearing masks, one of which had an exemption while the four others were made to put them on.

The incident was shared to Facebook by a parishioner, who wrote "a policeman allowed himself in, strutting up the aisle demanding correct mask behaviour and checking exemptions."

"Where have we seen this behaviour before in history?

Police said in a statement they responded to a report from a member of the public of people not wearing masks inside a church in Mount Hawthorn.

"Upon attendance, 5 people were spoken to by police and complied in wearing a mask," they said.

"One person provided proof of an exemption."