BERLIN (AP) – German authorities on Tuesday arrested the wife of a Tunisian man detained last month over a plot to use the toxin ricin to carry out an attack in Germany, alleging that she was an accomplice.

Federal prosecutors said the 42-year-old German, named only as Yasmin H. in line with local privacy rules, is suspected of helping prepare an act of violence and helping produce biological weapons. Her husband, Sief Allah H., was arrested on June 12.

Prosecutors previously said that about 3,150 castor bean seeds and 84.3 milligrams of ricin were found at the main suspect’s Cologne apartment, along with components needed to make a bomb. Tiny amounts of ricin can kill an adult if eaten, injected or inhaled.

The couple bought a hamster to test the effectiveness of the substance, according to prosecutors, adding that the rodent is alive and well at an animal shelter.

Investigators say that Sief Allah H. twice traveled to Turkey last year in hopes of getting to Syria to join the Islamic State group. According to prosecutors, his wife – who didn’t travel because she has children from a previous marriage – contacted people who she hoped could facilitate their way to IS and booked his plane tickets to Turkey in August and September.

Last fall, Sief Allah H. allegedly contacted IS members in Syria, who proposed that he carry out an attack in Germany. In October, he visited a pyrotechnics company in Slubice, a Polish town on the border with Germany, a trip that prosecutors say his wife arranged.

They alleged that she helped him place and pay for some of his orders for equipment and the castor bean seeds. Prosecutors say he managed to produce 84.3 milligrams of ricin at the end of May.

“If we hadn’t intervened, if police hadn’t arrested him then, there would probably have been a serious attack,” Hans-Georg Maassen, the head of Germany’s domestic intelligence agency, told reporters in Berlin.

Authorities have said that German security agencies were first warned about the man by foreign intelligence agencies, but the information provided wasn’t conclusive enough to act upon. A phone-in tip from the public then helped them confirm their suspicions.