A Perth police officer is under investigation after he was filmed pulling the middle finger and threatening a member of the public after being asked to reveal his badge number.

The brothers involved in the abusive display say they are appalled by the officer’s behavior.

“You want to be able to approach these people and not feel intimidated by them,” one of the brothers said.

View photos The constable was filmed giving the middle finger to a member of the public. Source: 7News More

The constable had arrested one of the men after a failed roadside breath test in Carlisle on Friday night.

The arrested man’s brother then films the officer on a mobile phone, repeatedly asking for his official number.

“Hey bro, what’s that?” the 20-year-old can be heard asking as the officer gives the offensive gesture.

View photos The constable is filmed giving the middle finger. Source: 7News More

“Can you do that again for the camera?”

The constable did reveal his badge number but after several minutes of questions from the 20-year-old, he’d apparently had enough.

“Get out of the car or I’m going to smash your camera,” the constable is filmed telling the man.

The man was arrested, hand cuffed and told he’ll be charged with obstructing police.

He can be heard telling the officer he has “done nothing wrong” during his arrest.

The brothers have since lodged an official complaint with police.

View photos WA Police Commissioner Karl O'Callaghan. Source: 7News More

Police Commissioner Karl O’Callaghan said the behaviour of the constable was “unprofessional”.

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