31-year-old Stefanie Pieper was known for her singing, make-up and fashion.

Her ex-boyfriend confessed to killing her during an interrogation that went for seven hours.

"It is now a sad certainty: the missing woman was found dead in Slovenia - and this during the 16 days against violence against women. During the interrogation yesterday, the 31-year-old confessed to the crime," Provincial Police Director Gerald Ortner told Kronen Zeitung, an Austrian newspaper.

Markus Haas from the Styrian State Criminal Police Office told the newspaper on the course of the investigation: "On the evening of November 23, a colleague of Stefi's alerted the police because she had not come to the agreed meeting. The police rushed to her apartment, where they found her dog and her ex-boyfriend. The 31-year-old said he was only looking after the dog, but there was blood on the doorpost. However, this was not enough for an arrest."

Witness interviews were started immediately. And these revealed explosive details: a violent argument had been noticed at around 8 o'clock that morning, and a short time later the 31-year-old Slovenian had been seen walking out of the apartment "with a kind of tarpaulin or rug on his shoulder", Markus Haas said.

Surveillance cameras even showed that the suspect drove across the Slovenian border and back to Styria that same afternoon.

Stefanie's cell phone was even traced in Graz.

During an interrogation, the suspect confessed that he murdered the 31-year-old woman from Graz, packed her in a suitcase and taken her to Slovenia in the back of his car.

The suitcase was buried in a wooded area located close to Mašperk.

The suspect has been sent to  Graz-Jakomini prison.

If convicted, he will face up to 20 years or even life imprisonment.