A "completely innocent" businessman has won £40,000 damages from a former Ukip official over a tweet which falsely accused him of child grooming.

Zahir Monir, 39, of Rotherham, South Yorkshire, brought libel proceedings at London's High Court against Steve Wood, the ex-chairman of the party's Bristol branch and candidate for Bristol South at the May 2015 general election.

In a ruling on Wednesday, Mr Justice Nicklin found that the allegation was "life-changing" and had transformed the lives of Mr Monir and his family "for the worse".

He said: "It needs to be stated clearly: Mr Monir is completely innocent.

"He has been seriously libelled. He has been forced to fight a libel claim all the way through to trial with every single conceivable point being taken against him."

The judge added: "The strain that it has put on him was obvious to me when he gave his evidence.

"I am doubtful even the success in this claim, the award of damages and his public vindication through this judgment will restore him to the life he enjoyed before this libel."

The tweet, published on Bristol Ukip's official Twitter account on May 4 2015 three days before the election, was written and posted by John Langley - the branch's vice-chairman at the time.

It featured a photo of Mr Monir and another individual standing either side of Labour MP Sarah Champion, with the statement: "Sarah Champion labour candidate for Rotherham stood with 2 suspended child grooming taxi drivers DO NOT VOTE LABOUR".

It was published to @BristolUKIP's 547 followers, re-tweeted at least 17 times, liked at least eight times, published on the official Bristol Ukip webpage and republished on Facebook.

One of those who shared it was English Defence League founder and convicted fraudster Tommy Robinson, whose Twitter account at the time had 138,000 followers.

It had been devastating for Mr Monir's family and he had been diagnosed with depression.

His property had been egged and a brick thrown through a window, while he had been called "Jimmy Savile" by another parent at the school where he was previously a parent governor.

Mr Justice Nicklin said Mr Monir, a Labour supporter who had been active in local politics and involved in charity and community work, had not only suffered "hurt and embarrassment" but also "genuine fear and distress".

He said: "Mr Monir has become something of a recluse, afraid to carry on his normal life.

"The consequences of that extend beyond Mr Monir and touch his whole family.

"Of course, damages for libel cannot compensate their hurt, but it is legitimate for the court to reflect the hurt caused to Mr Monir by seeing the impact on his family of his suffering."

The judge said that, had the allegation been published in a national newspaper, he would have awarded damages of £250,000.

Although Mr Langley wrote the tweet, Mr Justice Nicklin found he was "quite clearly acting as the agent of Mr Wood" at the time.

The judge said Mr Wood, a former police officer who now runs a bailiff firm, had adopted a "mean-spirited stance" by refusing to publicly apologise and withdraw the allegation.

He added: "He has become completely convinced that he has done nothing wrong and therefore he will not apologise for or retract the allegation.

"On a simply human level, this is a difficult stance to understand."

He said Mr Wood could have maintained that he was not responsible for the publication, but "done the decent thing" of making it clear there was "absolutely no truth in the allegation" contained in the tweet by an organisation of which he was chairman.

Mr Monir's solicitor, Jeremy Clarke-Williams, of law firm Pennington Manches, said: "The publication of the vile and baseless tweet for cynical political reasons has caused huge damage and distress to Zahir Monir and his family.

"This judgment provides him with the complete vindication he deserves.

"He has had to endure more than three years of suffering and stress to achieve this victory and the failure of the defendant to apologise for or retract the allegation is, as the judge noted, 'On simply a human level ... a difficult stance to understand'."

Mr Clarke-Williams said the judgment was "extremely important" from a legal point of view and will have to be considered carefully by those who have social media accounts which others operate on their behalf.

He added: "If you are responsible for letting a maverick genie out of the bottle then you are likely to face the legal consequences - and in the era of fake news that presents a real risk."

By Sian Harrison