Investigators in the northwestern town of Schloß Holte-Stukenbrock believe that the 56-year-old suspect may be linked to the deaths of up to 21 company employees.
The man, who has been working for ARI Armaturen for 38 years, was arrested in May after one of his colleagues found an unknown white powder on his food.
The powder turned out to be lead acetate, a highly toxic substance that can cause serious organ damage.
A subsequent search of the suspect’s home revealed quicksilver, lead and cadmium which are substances used to make poison.
Investigators are looking for leads that may link the suspect to the deaths of 21 more company employees who have died since 2000; many from cancer or heart attacks, which experts said could have been the result of heavy metal poisoning.
Two other people are now in a coma and another one on dialysis.