The leader and deputy leader of far-right group Britain First, who hit the headlines after U.S. President Donald Trump retweeted anti-Muslim videos the group posted, were found guilty of religiously-aggravated harassment on Wednesday.

Paul Golding, 36, and Jayda Fransen, 31, were convicted for filming and posting online videos of people who they wrongly believed were defendants in a rape trial at Canterbury Crown Court in May last year, which led to the conviction of three Muslim men and a teenager.

They also posted offensive leaflets to houses in the area where the defendants lived.

Judge Justin Barron at Folkestone Magistrates' Court said Golding and Franson had "demonstrated hostility" towards the Muslim faith.

"I have no doubt it was their joint intention to use the facts of the case (in Canterbury) for their own political ends," he added.

"It was a campaign to draw attention to the race, religion and immigrant background of the defendants."

Prosecutor Jaswant Narwal said the case had demonstrated Golding and Franson "were not merely exercising their right to free speech but were instead aiming religiously-aggravated abuse at innocent members of the public".

"The victims suffered the distress of the abuse followed by additional stress when the footage was uploaded to the internet," he added.

Trump's sharing in November of three inflammatory anti-Muslim videos posted by Britain First, unrelated to the videos in the Folkestone trial, sparked a Twitter row with British Prime Minister Theresa May.

The retweeting of the controversial videos led to renewed calls for Trump's planned state visit to the UK to be canceled.

He later made a rare apology, saying he did not know the group's background before retweeting.