A former BBC Radio Leeds presenter launched a relentless nine-year campaign of stalking against eight victims, including ex-colleagues and TV presenter Jeremy Vine, a court has heard.

Nottingham Crown Court was told that Alex Belfield repeatedly posted or sent mocking and abusive social media messages, videos and emails after his one-year contract was not renewed in 2011.

Prosecutors allege that the 42-year-old caused serious alarm or distress to Channel 5 and BBC Radio 2 presenter Mr Vine, former BBC Radio Leeds mid-morning show host Stephanie Hirst, and BBC Radio Northampton’s Bernie Keith.

Opening the Crown’s case against Belfield, prosecutor John McGuinness QC said Mr Vine was subjected to a “constant bombardment” of harassing tweets and YouTube videos in 2020.

The presenter, the court heard, faced a wave of abuse online after false and entirely baseless claims were made relating to the supposed theft of £1,000.

Belfield is said to have developed a “dislike, almost hatred” of Mr Vine after the BBC donated the sum to a memorial fund set up to honour a friend of the broadcaster.

The court heard that Ms Hirst felt the conduct against her had been sickening, misogynistic and  transphobic, while Mr Keith said the alleged stalking had a devastating effect and had prompted him to install additional home security.

Mr McGuinness told the court the offences alleged by the Crown began in November 2012 – a year after Belfield’s one-year contract at BBC Radio Leeds was not renewed.

The Crown allege that Belfield “wasn’t prepared to move on” after leaving the BBC and became disgruntled by what he perceived to be unfair treatment from his managers.

Mr McGuinness told the court: “It is not suggested the defendant’s conduct involved physical stalking… although such was the effect of what Alex Belfield did that some were, in fact, worried about the possibility of Mr Belfield turning up at their homes.

“The stalking which this case is concerned with is of a different type – and is more akin to internet trolling.

“The alleged victims did not want to be contacted by Alex Belfield, they did not want to see or hear or know what it was that he was saying about them.

“But he went ahead and he did it anyway, the prosecution says, relentlessly harassing them, knowing or being aware he was harassing them – to the extent that what he did caused them serious alarm or distress which affected their daily lives for the worse.”

Mr McGuinness told the trial: “Everyone has the right to express their opinion in the democratic society in which we all live.

“The prosecution case is that what Mr Belfield did with the eight people named in the counts went beyond that which is allowed – and became stalking, which is a criminal offence.”

Addressing the specific count concerning Belfield’s contact with Mr Vine, Mr McGuinness said: “Mr Vine had no knowledge or awareness of Mr Belfield until about April 2020.

“However, in the three months or so after that, the prosecution says, Mr Vine was subjected to a constant bombardment of harassing tweets and YouTube videos.”

Mr McGuinness told the court the TV presenter had no idea that the BBC had even made a donation and “certainly didn’t steal it”.

Giving details of the “personal and unpleasant” abuse directed towards Mr Vine, the QC said it had included foul language and a “ludicrous” untrue claim that the broadcaster had “signed his 10-year-old daughter up as a company director”.

The lies affected Mr Vine’s sense of wellbeing and optimism, the court was told, and he was concerned at Belfield’s attempt to obtain private information.

When Belfield was interviewed by the police, he told officers he was the subject of a witch hunt, the jury heard.

Mr McGuinness told the court: “He said the BBC had legally trained him but he was a whistle-blower and a thorn in the BBC’s side.”

The court heard that Belfield, of Mapperley, Nottingham, started out as a broadcast assistant on local radio and in recent years set up a YouTube channel known as Celebrity Radio.

He denies eight counts of stalking alleged to have been committed between 2012 and 2021, including three counts relating to two managers and another presenter who worked at BBC Radio Leeds.

The trial, which is expected to last for several weeks, continues.