Lau, 35, was arrested on Tuesday in the city of Monchengladbach, North Rhine-Westphalia (NRW), the most populous state in Germany.
Ralf Jaeger, North Rhine-Westphalia’s interior minister, has described Lau as “one of the leading figures” among German Salafists.
“With their propaganda glorifying violence and their alleged help for suffering people in war zones, Salafist preachers such as Lau provide a breeding ground for the radicalization of young men,” Jaeger said. “They are inciting young people to join jihadist terror groups in Syria and Iraq.”
Investigators suspect Lau of supporting Jaish al-Muhajireen wal-Ansar (JAMWA), an Al-Nusra Front affiliate. He was allegedly a JAMWA coordinator in the NRW, helping extremists to leave for Syria to join the war.
Lau is known in Germany for organizing the so-called ‘Sharia police’ in the city of Wuppertal.