LONDON - A BRITISH protestor who tried to extinguish the Olympic flame as it passed through London en route for Beijing walked free on Monday, after a judge found in his favour.

Martin Wyness, 50, set off a fire extinguisher and aimed it at the flame on Apr 6, when hundreds of thousands lined the streets amid tight security for the flame, on its way to China for the Aug Games.

Video footage of the incident showed Wyness, dressed in a high visibility jacket, aiming a white substance at the flame from the extinguisher, labelled 'Propaganda Extinguisher,' before being detained by police.

Judge Andrew Sweet agreed with Wyness' defence lawyer that there was not enough evidence to prove he had intended to cause harassment, alarm or distress, as charged.

'Having viewed the video footage and listened carefully to your argument, I am not satisfied that the elements (of the charge) are made out. Your application succeeds,' he said, awarding 300 pounds (S$774) in costs to Wyness.

The court heard how Wyness had told television cameramen after the incident, 'I tried to extinguish the flame. China has no right to be doing what it's doing.'

Policeman Doug Dinning said he saw Wyness pulling the extinguisher from a backpack. 'I then grabbed the nozzle with my left hand. My immediate thought was that he was going to discharge it within the crowd and to the flame.

'It left a white haze. I did not know what sort of extinguisher it was or what was being discharged. There was quite a lot of shouting. It was a noisy event,' he said.

Sporadic scuffles broke out and nearly 40 people were arrested during the London leg of the Olympic relay, which was clouded by protests over the Chinese crackdown in Tibet.

London will host the next summer Olympic Games in 2012. -- AFP