German prosecutors say they're reopening their investigation of a man suspected of joining the Islamic State group after his name surfaced on one of the organization's recruitment questionnaire forms, leaked and published earlier this year.

Duesseldorf prosecutor Ralf Herrenbrueck told the Sueddeutsche Zeitung newspaper Wednesday that a slightly changed version of Ugur S.'s name and his correct birthday and date of travel appeared on one of the forms.

S., whose last name wasn't given in line with German privacy laws, was acquitted earlier this year of extremism-related charges for lack of evidence. Herrenbrueck, who couldn't immediately be reached for comment, says the case is now being examined by federal prosecutors to determine whether new charges can be brought.

The 31-year-old suspect is already in custody for unrelated criminal activity.