Inside Denmark’s Most Secret Prison Witness Case

Edward Walgwe

December 21, 2025
6:04 am

Former biker and police informer “The Golden Bird” lived under intense prison security at Nyborg Prison before helping convict 15 members of the Hells Angels and AK81. He now lives abroad under full witness protection.

Unprecedented Security Around a Key Witness

In the early 2010s, Nyborg Prison on the Danish island of Funen became the center of one of the most secretive security operations in Danish history. The facility held Martin Fryd Petersen, better known by his codename “The Golden Bird.” Once part of the biker group AK81, Petersen became the police’s main witness in what was later known as “the great biker case.”

His testimony helped secure 135 years of prison sentences against 15 members of the Hells Angels and its support club AK81. That cooperation with police also meant Petersen’s life was in danger. Danish authorities worked with the national intelligence service PET to hide and protect him as he prepared to testify.

Life Inside Nyborg Prison

Few people inside Nyborg Prison even knew who he really was. Sources with knowledge of the prison’s operations describe how Petersen was kept completely isolated in a specially secured wing. Only a small group of trusted staff had access to him, and his legal name never appeared in standard prison records.

Keen security measures surrounded everything about his custody. When he was taken to court, transfers happened quietly at night. Convoys of dark armored cars arrived under helicopter surveillance, entering and leaving without attracting attention. Those operations continued until the final stages of the trials that dismantled the biker network.

Similar strict measures have recently surrounded Danish crime investigations linked to gang and tax-fraud cases, like those described in Danish gangs investigations where secrecy and protection remain essential for witnesses and police officers.

Total Reinvention Under Witness Protection

After the trials, Petersen vanished from public life. He is one of very few Danes living under full witness protection abroad. His face and name were permanently changed, and every link to his old identity and family was cut. Today, he lives in another country under a new cover story designed to survive any scrutiny.

His story shows that turning against biker gangs often comes with lifelong consequences. Former insiders rarely get a second chance without enormous personal risks. The secrecy and coordination around Petersen’s protection highlight how far Danish authorities will go to hide crucial witnesses.

The newly published book *Guldfuglen – Det næste liv* (“The Golden Bird – The Next Life”) by journalist Marie Louise Toksvig describes how his past continues to shape his hidden present. It is a rare look into a Danish witness-protection case that remains shielded even years later.

A Case That Changed Danish Organized Crime

Petersen’s cooperation with law enforcement marked a turning point for Danish biker crime. His testimony helped break the inner circles of Hells Angels and AK81 at a time when organized biker violence was escalating throughout Denmark.

Without his detailed account of gang life, investigators would likely have struggled to secure convictions. His move from a violent biker world to total anonymity demonstrates the extremes of Denmark’s legal and security systems.

For Danish authorities, the “Golden Bird” case became a model for handling future high-risk witnesses. Security levels at Nyborg Prison and coordination with PET have since served as examples in police training and internal reforms. Even years after his cooperation, official records about the case remain heavily restricted.

The operation also stands as a reminder of how organized crime and witness protection intersect within modern Denmark’s judicial system. Behind the closed walls of Nyborg Prison, one man’s testimony reshaped the balance between gangs, law enforcement, and the safety of those who choose to speak out.