One of two men suspected of terrorism in Germany was released on Monday, officials said, after they were arrested on suspicion of planning a bio-weapons attack earlier this month.
The Dusseldorf chief public prosecutor's office said the Dortmund district court in northwest Germany currently saw no urgent suspicion that one of the two Iranian brothers intended to commit a crime, after both were suspected of obtaining hazardous substances. The 32-year-old's arrest warrant was lifted.
"The investigations, however, are of course continuing," senior public prosecutor Holger Heming told dpa on Monday evening. He was unwilling to provide further comment.
The brothers, aged 32 and 25, were taken into custody in the town of Castrop-Rauxel, north-west of Dortmund, for allegedly planning an attack using cyanide and ricin with the intent of killing "an unspecified number of people," prosecutors said.
No toxins were found, but North Rhine-Westphalia's Interior Minister Herbert Reul said investigators had identified "minute quantities of chemical and biological substances."
Investigations are continuing into the younger of the two brothers, after both were detained at the start of the month.
