The former chief executive of the Football Association (FA) has described the stress and anxiety he suffered after a fantasist accused him of corruption and covering up child sexual abuse on Twitter.

Craig Kline, previously a director of football at Fulham FC, made a string of claims against Martin Glenn after quitting the club in December 2017.

His campaign of harassment began in November 2018 and continued into the summer of 2020.

He alleged Mr Glenn – who has since been made chairman of the Football Foundation charity – was instrumental in covering up corruption, child abuse and fraud at Fulham between 2014 and 2017.

The allegations prompted the FA to launch an investigation, which reported in December 2018 that it found no evidence of any wrongdoing.

It also stated Mr Kline himself had produced no evidence to support his allegations.

At a High Court hearing in November, a judge ruled in favour of Mr Glenn in his libel case against Mr Kline after the defendant failed to file any kind of defence.

At a hearing to decide damages on Tuesday, Mr Glenn said: “The allegation that I was complicit in child abuse was absolutely terrible particularly as I was responsible for the safeguarding of children.”

Mr Glenn said while at the FA, he had been responsible for developing and implementing a “robust” safeguarding policy to be adopted by about 20,000 football clubs across England.

“Following the revelations from the (former football coach and serial child abuser) Barry Bennell case, the FA was – under my leadership – really taking its responsibilities very seriously,” Mr Glenn said.

“We really spent a lot of time and effort trying to improve the environment that children were playing in and we were held up by the NSPCC and Sport England as the absolute exemplar of how a (policy) should be set out.”

Mr Glenn said that among other measures, the FA had appointed an auditor to ensure that its child safeguarding policies were being enforced at grassroot clubs.

The claimant said he had delayed libel proceedings against Mr Kline – whom he has never met – because he didn’t want to give him more publicity.

He said he was eventually forced to take action after several prospective employers noticed reports of the FA’s investigation in the press.

“I need the wherewithal to demonstrate to third parties the absolute untruth and maliciousness of the campaign Mr Kline has waged against me,” Mr Glenn said.

“I need to be able to show people (the claims) are unambiguously false.”

Mr Kline, who describes himself as a “whistle-blower” on his social media accounts, did not join the hearing and is understood to be living in Spain.

Mr Glenn said the campaign had been upsetting for his family, particularly his children whom he described as “social media natives”.

He said there had been a “background level of concern” in his household about the harassment, and that his wife had been concerned Mr Kline might track down their address.

He said that during his last year with the FA, he had to tell the security team of the risk posed by Mr Kline in case he turned up at any of the England camps.

“Calling me a ‘known criminal’, calling me a ‘coverer up of paedophile rings’ – these are absolutely terrible things to say,” Mr Glenn said.

Alexandra Marzec, for Mr Glenn, said that Mr Kline had linked the announcement of her client’s departure from the FA to his allegations.

“He used the announcement of my client’s resignation to suggest there was some kind of acknowledgement of guilt on the part of my client,” she said.

She added that Mr Kline had tried to use the fact that many news outlets had reported his initial allegations as evidence that they were true.

Mr Glenn initially sought £25,000 in damages but his legal team are now seeking £100,000.

“There has been no apology, no correction, no withdrawal – Mr Kline remains wholly unrepentant and maintains the claims are true despite the fact there is no evidence,” Ms Marzec said.

Judge Richard Spearman QC reserved judgement, but said he would try and get the judgement out “as soon as possible”.

In January, Mr Kline was fined £25,000 for contempt of court for 49 breaches of a court order made in November 2018 banning him from issuing any “derogatory or critical comments or statements” relating to Fulham FC on social media.

Mr Kline was told to pay the money in 12 monthly instalments.