Broadcaster Andrew Neil has launched defamation proceedings against American businesswoman Jennifer Arcuri.
Court records show the former GB News chairman and BBC presenter, 72, filed a claim against Arcuri on Wednesday.
Arcuri is listed as a litigant in person on the court filings, suggesting she does not currently have a legal representative.
It comes after the pair became embroiled in a tense Twitter exchange in December which culminated in Neil vowing to seek “exemplary damages” and warning his lawyers had “prepared a massive case” against Arcuri.
The row, which unfolded in December, is understood to have started over a disagreement about the effectiveness of Covid-19 vaccines before descending into personal attacks.
Neil accused Arcuri of “clear libel and defamation” after she tweeted allegations about his inclusion in an address book belonging to paedophile financier Jeffrey Epstein, The Guardian and Variety report.
Neil has previously denied ever meeting the convicted child sex offender and said he was listed in the deceased businessman’s “black book” because he had met Ghislaine Maxwell in New York in the 1990s.
He tweeted Arcuri on more than one occasion in December stating his intention to bring legal action against her.
In one he wrote: “I have clicked to follow you. Please DM your address/contact details so my lawyers can serve legal papers against you for this clear libel and defamation. I’ve instructed the papers to be drawn up now. All those tweeting support for and spreading her tweet will also be served.”
She responded by saying: “You really are threatened by me @afneil. Thank you for confirming. Now the world sees exactly what you are.”
In another he said his legal team “has prepared a massive case against you and we’ll be seeking exemplary damages”, adding papers would be served in the UK and US.
Both parties have been approached for comment.