Beauty Influencer Stefanie Pieper Found Dead in Forest

Stefanie Pieper -- an influencer from Austria -- has reportedly been found dead in a forest in Slovenia after her ex-boyfriend allegedly confessed to killing her.

Austria's largest newspaper, Kronen Zeitung, reports Stefanie's body was uncovered after investigators claimed her ex admitted to strangling her and took investigators to where he'd hidden the body.

The man has reportedly been extradited from Slovenia back to Austria, and his brother and stepfather have also been arrested.

Pieper was last seen Sunday at a holiday party ... and, friends and colleagues alerted the police when she didn't show up to a modeling shoot.

Police arrested Stefanie's alleged killer Monday after they found him near his burning vehicle. Border crossing data reportedly shows he made multiple trips between Austria and Slovenia in recent days.

Pieper was 31.