A California state judge has upheld an earlier jury verdict against Bayer, the owner of the Roundup brand, but reduced the damages awarded to former groundskeeper Dewayne Lee Johnson, according to US media reports.

In August, a jury had awarded €255m in damages to the Roundup user, who alleges that the glyphosate-based herbicide caused him to develop cancer.

A judge reviewing the case has confirmed the verdict against the manufacturer, but reduced the punitive part of damages, cutting the overall sum to be paid by Bayer to €68.5m.

Johnson must decide whether he accepts the sum and Bayer may appeal the verdict. Health authorities around the world have found that glyphosate, the active ingredient in Roundup and other herbicides, is safe to use. However, the World Health Organisation’s International Agency for Research on Cancer (IARC) has placed it on a list of chemicals deemed to be “probably carcinogenic to humans”.