German federal prosecutors confirmed that the 29-year-old Syrian suspect was turned over to Germany on Thursday.

Saleh A., whose full name has been withheld in accordance with German privacy laws, was detained in Paris in February.

He revealed to French investigators that an "Islamic State" (IS) cell planned to launch an attack on the western German city of Düsseldorf. 

Chilling revelations

The alleged plot involved two militants blowing themselves up in the historic quarter of the city, while other assailants launched gun and bomb attacks.

Their instructions came directly from senior IS leaders, prosecutors have said.

Saleh A's revelations led to the arrests of Hamza C., Mahood B. and Adb Arahman A.K. - all Syrian nationals - in three different German states in June.

The men, aged between 25 and 31, were living in refugee shelters. Before his arrest, Saleh A. was also living in a migrant center near Düsseldorf. 

He and the three other men will likely face charges of membership of a terrorist organization and of plotting an attack on German soil, but they have not yet been formally charged. Prosecutors said they all were arrested before they had formed a concrete plan.

Links to Islamist extremist groups

All four are suspected IS members, while Adb Arahman A.K. is also thought to have been involved in the activities of Jabhat Fatah al-Sham, a former al Qaeda-linked group previously known as the Nusra Front.

In July, German newspaper "Welt am Sonntag" said Saleh A's statements to police appeared to be fraught with contradictions.

The newspaper cited a German intelligence source as saying the 29-year-old was an "informer" for the federal intelligence service (BND).

mm/sms (AFP, dpa)