Mr Rippon, 31, pulled a 0.177-calibre pellet from his scalp. It was embedded centimetres from his left temple.

He referred to the mystery shooter as "a little junior terrorist" who was "obviously not showing a great deal of judgment".

"I am pretty sure this wasn't an accident," he said.

Mr Rippon, who works at the Prince of Wales Hospital at Randwick, in Sydney, was spending a few days at his girlfriend's house at Mount Hutton.

On Monday afternoon, he was standing outside the front of the Harmony Crescent house about 4pm when he felt something sharp on the side of his head.

"At first I thought it must have been a bee or a wasp - it was very painful," Mr Rippon said.

"But when I pulled it out I knew exactly what it was.

"I grew up in rural Canada and everyone had a trail bike and a pellet gun; it was just the way it was.

"We might have shot each other in the arse, never something like this.

". . . this is someone who is hiding from a bedroom window or a fence and taking pot shots."

He said he easily could have lost an eye or worse.

Lake Macquarie investigations manager Detective Senior Sergeant Chad Gillies said police were treating the incident very seriously.

Information can be passed on by phoning 4942 9999.