Influencer Stefanie Pieper vanishes after Christmas party: Boyfriend arrested as police probe blood traces and burned car

Stefanie Pieper, a 31-year-old beauty influencer and makeup artist from Graz, Austria, disappeared after attending a Christmas party on Sunday, November 23, 2025, prompting a major police investigation involving her on-off boyfriend's arrest.

Last seen around 7 am that morning, Pieper failed to appear for a scheduled photoshoot on Monday, November 24, leading her photographer to visit her apartment where he encountered her reported 31-year-old boyfriend, Peter M., an amateur poker player and part-time security guard.

Police found her phone discarded in a nearby bush, her Golden Retriever Marlow alone inside, and are examining potential blood traces in the apartment amid reports of "loud noises" from neighbors on Sunday.

Timeline and investigation details

Pieper returned home via taxi with a friend after the party at a nightclub where Peter M. was also present, though they reportedly did not interact. She messaged a friend confirming safe arrival, planned to walk Marlow in the morning, then sent a chilling final WhatsApp: "There's a creep in the stairwell," describing a dark figure.

Peter M. was arrested Monday evening, November 24, in Slovenia near the border after his red Volkswagen Golf was found burned in a casino parking lot in Šentilj; he struggled to explain the fire during questioning and faces extradition to Austria for a hearing.

Styrian State Police confirmed two other men are under investigation, with searches including sniffer dogs at Peter M.'s grandmother's garden; no confirmed sightings of Pieper, described as 5'9", slender, with shoulder-length dark blonde hair and a "Csilla" tattoo on her left forearm.

Her mother publicly appealed: "My daughter has been missing since Sunday. Any useful information will be financially rewarded. Please assist me in finding my daughter." Police dismissed rumors of her discovery in Slovenia, stating searches there yielded nothing and operations continue across borders.