Man Cops Life Sentence After Poisoning Work Mates' Sandwiches

A 57-year-old German man was found guilty of attempting to murder his work colleagues by sprinkling heavy metals onto their sandwiches and drinks.

Klaus O was arrested in May after being caught on camera putting a suspicious powder on his workmate's food in the regional town of Schloss Holte-Stukenbrock - in north-west Germany. 

It prompted police to investigate a string of 21 deaths at the business over two decades -- many of them from heart attacks -- but authorities later confirmed he was involved in at least three poisonings.

A 27-year-old and 67-year-old suffered chronic kidney damage after they ingested lead and cadmium, they now have an increased risk of cancer for life. 

A 23-year-old trainee has permanent brain damage after being poisoned with mercury.

Klaus O has not been identified  IMAGE: Friso Gentch/AP

When authorities searched Klaus O's home, they found a range of deadly substances which Judge Georg Zimmermann described as "more dangerous than all combat agents used in World War II".

On Thursday, he was handed the maximum possible jail term for his crimes -- a life sentence.

In Germany, that typically means 15 years.

It's not known why he laced the lunches over several years, he refused to speak during his trials, meaning his motive remains unclear.

IMAGE: Friso Gentch/AP

It's not the first time a mans been jailed for poisoning his workmates.

In 2018, 58-year-old New Zealander Graham Jones was sentenced to 22 months jail after taking a marijuana-laced cake into work.

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Nine of his colleagues were admitted to hospital after eating the space cake, many believed they were having a heart attack.