The Disappearance of Tanja Groen

The last known night

Tanja Groen was 18 and had recently moved from Schagen to Limburg to begin studying health sciences in Maastricht. On the evening of August 31, 1993, she attended a party at the Circumflex student association on Herbenusstraat in Maastricht.

After the party, Tanja set out for her student room in Gronsveld, roughly ten kilometres away. She never arrived. Police later said that neither her bicycle nor her personal belongings were recovered. Her parents reported her missing on September 4.

Decades of investigation

The disappearance became one of the Netherlands' best-known cold cases. Police and prosecutors pursued large numbers of tips and compared DNA profiles and other traces over the years. Search operations included the opening of a grave in Maastricht and excavation work on heathland, but none located Tanja or produced a conclusive explanation.

Authorities also examined possible links to other offenders and investigations, but no theory produced evidence sufficient to identify a perpetrator or establish what happened. Because those possibilities remained unproven, this page does not name speculative suspects.

The €1 million reward campaign

In 2021, Stichting De Gouden Tip, founded by crime journalist Peter R. de Vries, raised a €1 million reward in an effort to generate a decisive lead. Police said the renewed attention produced about 1,000 tips. The campaign did not lead to a breakthrough, and the funds were later released for other cold-case and victim-support work.

Final investigative review

Police and the Dutch Public Prosecution Service continued reviewing new information. In 2025 and early 2026, the Limburg cold-case team examined additional material, including information supplied by a prisoner. Authorities ultimately concluded that the latest avenues did not support a new search or resolve the disappearance.

On May 11, 2026, police and prosecutors announced that the active investigation had been completed after 33 years. They said serious information, tips, forensic traces and plausible scenarios had been examined without answering the two central questions: what happened to Tanja and where she is.

Current status

The case remains Unsolved. Closing the active investigation did not mean that authorities considered the mystery solved. Police said that if concrete new information or a credible decisive tip emerges, investigators will take it up again.

Tanja has never been found, no person has been convicted in connection with her disappearance, and there is no verified public account of what happened after she left Maastricht that night.