The authorities in Germany said early Sunday that they had taken into custody a 32-year-old Iranian citizen suspected of procuring cyanide and ricin in an effort “to commit an Islamist-motivated attack.”

In a brief statement released by the police in Münster, Germany, the authorities said that investigators had searched the suspect’s home in the city of Castrop-Rauxel for toxins and other evidence.

“The accused is suspected of having prepared a serious act of violence that endangers the state,” the statement said, adding that such a crime is punishable with a prison sentence of between six months and 10 years.

The police did not offer any additional information about the suspect. They said that they took one other person into custody in connection with the investigation, but provided no details about that person.

Prosecutors said that the investigation was continuing.

This is a developing story.