PHARMACEUTICAL giant Monsanto has denied its Roundup weedkiller causes cancer after a Californian court ordered it to pay $289 million (£226m) to a school groundsman who contracted non-Hodgkins lymphoma.

Monsanto’s German owners issued a statement on Saturday insisting glyphosate, the active ingredient in Roundup, is safe.

“On the basis of scientific conclusions, the views of worldwide regulatory authorities and the decades-long practical experience with glyphosate use, Bayer is convinced that glyphosate is safe and does not cause cancer,” it said.

Dewayne Johnson was awarded $250m in punitive damages and $39m in compensatory damages on Friday because Monsanto failed to warn that Roundup may cause cancer.

Monsanto said it would appeal the ruling, which could pave the way for around 800 more Roundup compensations claims.

Robert F Kennedy Jr, representing Mr Johnson, said: “This jury found Monsanto acted with malice and oppression because they knew what they were doing was wrong and [were] doing it with reckless disregard for human life.

“This should send a strong message to the boardroom of Monsanto.”