Updated

The wife of a Tunisian man detained last month over a plot to use the toxin ricin to carry out an attack in Germany was arrested on Tuesday on suspicion of being 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.

Investigators say that Sief Allah H. twice tried to travel 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. At the end of May, prosecutors say he managed to produce 84.3 milligrams of ricin.

The couple then bought a hamster to test the effectiveness of the substance, according to investigators. Their plans were foiled when the husband was arrested shortly after.

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.