Nationals MP George Christensen has been reported to police over a social media post in which he uploaded an image of himself holding a gun, accompanied by a caption appearing to threaten "greenie punks".

It comes just days after the deadly shooting at a Florida high school in the US, which claimed the lives of 14 students and three teachers.

On Saturday, Mr Christensen posted a photo to Facebook of himself with a rifle at a Mackay shooting range, along with the caption "shooting is a great sport".

"Shooters don't deserve to be demonised like they are by the media and the Left — gun owners aren't criminals," Mr Christensen wrote.

In the comment section of the post, Mr Christensen uploaded a second photo of himself aiming a handgun, along with the caption: "You gotta ask yourself, do you feel lucky, greenie punks?"

The comment was later edited to read: "You gotta ask yourself, do you have a sense of humour, greenie punks?"

A short time later the post was deleted.

MP George Christensen's Facebook post ( Facebook: George Christensen )

Post reported to police

Greens leader Richard Di Natale said he reported the "disgraceful" post to the Australian Federal Police.

"[I] have asked Malcolm Turnbull to instruct him to take it down and apologise," he tweeted.

"Seventeen kids gunned down in cold blood and he thinks this is OK? He's not fit to be an MP."

Environmental activist Ben Pennings said he also reported the Facebook post to authorities.

Mr Pennings said Mr Christensen was an "appalling example to his constituents" and "should be ashamed of himself".

"When tensions are high, threats of physical violence to peaceful protesters are particularly unacceptable," Mr Pennings said.

The Stop Adani campaigner said he had added Mr Christensen's post to a complaint he filed with Queensland police on Thursday, after receiving abuse and death threats online.

"We shouldn't allow bullies to be federal MPs," Mr Pennings said.

Queensland police said they were aware of the image, and that preliminary inquiries indicated no offence had been committed.

Greens senator Sarah Hanson-Young criticised Mr Christensen, saying his behaviour was particularly inappropriate in a time of mass shootings and called him a "dangerous idiot".

"A Member of Parliament inciting violence against a group of voters should be a sackable offence," Senator Hanson-Young wrote on Twitter.

"If the leader of the Nationals had any class he'd sack him."

The ABC has contacted Mr Christensen for further comment.