Conor McGregor: Cops Investigate Gun Photo ... Looks Like a Fake

UFC champ Conor McGregor is under investigation by cops in Ireland for a gun related violation ... after he posted a pic of what appears to be himself with an automatic rifle.

Conor's back home in Dublin and on Thursday he posted a photo of someone wearing a ski mask and holding the gun while sitting in a fancy sports car. He captioned the pic, "Put the fight game in the bag and step away from the vehicle."

There's no way to tell for sure it's Conor with the gun, but the car does look like his. Ireland has very strict gun laws -- most civilian weapons are licensed only for hunting or agriculture -- and cops in Dublin confirm they are looking into McGregor's photo.

However, there's some evidence this is just a case of big boys playing with their toys. Last week, Conor posted a few videos of himself shooting at a target in his kitchen. The guns in those vids are clearly Airsoft pellet guns.

Problem is, according to police even brandishing an Airsoft gun in public could be a violation.