German prosecutors say there is no evidence that an Iraqi man detained after bomb blasts hit a top soccer team's bus was involved in the attack.
Prosecutors said on April 13 that the 26-year-old man is suspected of being a member of the extremist group Islamic State (IS).
However, they said in a statement that "so far the investigation has turned up no evidence that the suspect participated in the attack" in Dortmund on April 11.
Three bombs went off near a Borussia Dortmund team bus as it was heading from the team's hotel to the stadium for a Champions League match, shattering a window on the bus and injuring a player and a police officer.
Prosecutors said the Iraqi man allegedly joined an affiliate of IS in Iraq in 2014 and led a unit of about 10 fighters involved in preparing kidnappings, extortions, and killings.
They have asked a court to keep him in investigative detention.