Over 1,200 police officers were deployed across northern Germany to raid known Hells Angels' haunts on Thursday – including pubs, brothels and houses.
Police were led to a warehouse in the Altenholz area outside the city of Kiel, Schleswig-Holstein, where they suspect the body of a missing man, 47-year-old Tekin Bicer, has been cemented into the floor by the gang.
State prosecutors said on Friday that investigators emptied the building and are currently scanning it with special equipment. But they did not say whether Bicer, who had been missing since April 2010, had previously been linked to the biker gang.
Kiel was a focal point for the raids, with police storming 87 addresses and arresting five leading Hells Angels members. They also confiscated several knives, guns and machetes, along with computers and mobile phones.
Prosecutors are now investigating 69 members of the gang on a total of nearly 200 potential counts of sex trafficking, assault, corruption and illegally selling guns – possibly to far-right extremist party the National Democratic Party (NPD).
Thursday's raids were the largest-ever against the Hells Angels of northern Germany.
The biker gang is often linked to criminal activity in Germany and violent clashes with other gangs.