An Islamic terrorism plot to launch a deadly attack with the toxin ricin was reportedly thwarted in Germany, prosecutors revealed Thursday.

Authorities said a 29-year-old Tunisian, identified only as Sief Allah H., was taken into custody Wednesday after an investigation uncovered he had procured the materials needed to create ricin in mid-May and even succeeded in creating the toxin earlier this month.

Investigators found the toxin after a search of his apartment in Cologne, federal prosecutors in Karlsruhe said in a written statement.

"He procured 1,000 castor bean seeds online as well as an electronic coffee grinder," they said. The shell of the castor bean plant seed is highly poisonous and can be used to create ricin.

Prosecutors said they are still investigating exactly how the suspect planned to use the toxin, and said he was working on a “biological weapon” attack in Germany.

There is currently no evidence of a connection with any extremist organization, authorities said.

Prosecutors have not commented on a report by Bild newspaper that American intelligence tipped of Germany investigators. The newspaper also reported the suspect bought bomb-making material and chemicals used in the production of ricin.

If inhaled, ricin causes difficulty breathing and other symptoms. If ingested, symptoms include vomiting, diarrhea, hallucinations and seizures. Initial symptoms of ricin poisoning are most likely to occur within four to 10 hours of exposure.

Bild wrote that the suspect lived in the Chorweiler neighborhood of Cologne with his wife and four children. He supposedly used instructions for the making of a ricin bomb that had been posted online by the extremist Islamic State group.

The Associated Press contributed to this report