Council bosses say they are still looking for ways to reduce the use of controversial chemical weedkillers, in the light of a United States court verdict.

Norwich City Council has long used glyphosate-based weed killers, but concerns have been raised about its impact on human health.

In 2015, the World Health Organisation said they 'probably' caused cancer, although several other organisations did not come to the same conclusion.

And a court in the United States has ordered Monsanto, manufacturer of the glyphosate-based brand Roundup, to pay a man, who said he had sprayed the herbicide for three decades, millions of dollars in damages after he developed cancer.

Bayer, the owners of Monsanto, has appealed against the verdict, saying in a statement: 'This verdict does not change the weight of over four decades of extensive science and the conclusions of regulators worldwide that support the safety of our glyphosate-based herbicides and that they are not carcinogenic.'

A spokeswoman for Norwich City Council said: 'We keep our use of glyphosate to an absolute minimum when targeting weeds and we don't blanket spray as it is illegal.

'We will continue to look at different ways to reduce pesticide use wherever possible and will remain open minded to alternative solutions.'

Two years ago, the council asked its contractor Norse to look at potential alternatives to using glyphosate-based weedkillers.

A trial was conducted in Earlham Cemetery, with vinegar among the substances tested. However, the council did not find vinegar was effective against long rooted weeds.

At the time, Kevin Maguire, Labour's cabinet member for safe city environment, said no 'equally effective and comparably priced' alternative to glyphosate-based products had been identified.

Denise Carlo, the leader of the Green group at City Hall had pushed for a plant-based non-toxic foam called Foamstream to be tested.

But Mr Maguire had said: 'For Foamstream and other alternatives, as trialled both here and in other parts of the UK, test results are variable and inconclusive.'

He said the council would need to see a 'persuasive body of evidence' to support any proposed alternative.