'Sandwich Killer' May Have Killed 21 Colleagues By Poisoning Lunch

Twenty-one employees of the company had died prematurely.

Germany may have another serial killer on its hands.

Police in Bielefeld in north-west Germany are investigating the deaths of 21 employees of the same company after a man was arrested on suspicion of trying to poison a colleague's sandwich.

A 56-year-old man was arrested in May after being allegedly caught on CCTV sprinkling a powder on a 26-year-old colleague's sandwich.

The colleague noticed the powder on his bread and informed his superiors, who then installed a video camera in the break room.

The camera caught the 56-year-old, known only as Klaus O, opening a workmate's lunchbox and sprinkling a suspicious powder.

The powder is alleged to be a lead acetate, in a quantity that can cause severe organ damage, according to Bielefeld police.

A search of the suspect's home found a "kind of laboratory," said police spokesperson Achim Ridder, with mercury, lead and cadmium found.

Police are now investigating the early deaths of 21 employees at the company, "of whom a striking number have died of heart attacks and cancer." The suspect has been an employee of the company for 38 years.

According to experts, heavy metal poisoning -- which can be hard to detect -- can cause heart attacks and cancers.

A 15-strong team has been established to investigate the deaths.

They are speaking to relatives and treating doctors and reviewing medical records before determining if the bodies will be exhumed.

There are also two mysterious cases of severely ill colleagues, one of whom is in a coma, reports local media. The other is on dialysis.

"The accused remains silent on the allegations, so that the motive remains unclear," said police.