Editor-in-chief of the non-profit-newsroom CORRECTIV.
He is one of the founders of the investigation “The CumEx-Files” He authored 10 investigative books, including bestsellers on scandals in intelligence, politics and healthcare.
In 2010, he established the investigative unit of stern magazine and was its head until he moved to ARD investigative program Panorama.
He first reported about CumEx in 2014 for stern magazine. Together with colleagues he revealed the extent of the scandal for Panorama magazine. His award-winning investigations and his growing collection of the files forms the basis for “The CumEx-Files."