The Nottingham Forest owner, Evangelos Marinakis, has launched a £2.1 million High Court libel claim against a Greek club owner’s “smear campaign” accusing him of being a crime boss, match-fixer and suspected heroin trafficker.

Marinakis, a billionaire shipping magnate who also owns Greek Super League side Olympiacos, is suing Irini Karipidis, the owner of league rivals Aris, over a list of allegations published online last year.

A hearing on Thursday was told the allegations, which Marinakis vehemently denies, include “match-fixing practices including extortion, fraud and arson”.

Claims allegedly published online by Karipidis add that Marinakis transported oil through his shipping companies in breach of sanctions and that he was involved in a high-profile drug trafficking case in Greece.

David Sherborne, for Marinakis, said in written submissions: “The allegations which Mr Marinakis complains of are completely untrue and nothing in the defendants’ evidence comes anywhere close to substantiating them.”

He continued: “[The claims] involved false allegations highly defamatory of Mr Marinakis, making accusations that he was guilty of being leader of a criminal organisation, guilty of match-fixing practices including extortion, fraud and arson, as well as there being strong grounds to suspect him of deep and active involvement in international heroin trafficking (and) to hypocrisy and cynicism on his part in publicly criticising the Russian Federation’s 2022 invasion of Ukraine.”

The court heard that allegations were made against Marinakis on a website “nottinghamforestfire.co.uk”, with three articles published in November 2023.

Lawyers for Karipidis told the hearing in London that the case should be dismissed as an English court “is not clearly the most appropriate place” for the claim, which “lacks merit”.

But barristers for Marinakis, who has owned the Premier League team since 2017, said the allegations were “completely untrue” and that the case should proceed in an English court as it had a “real prospect of success”.

An account was also created on X, with several posts published in December 2023, and six videos uploaded to a YouTube channel. The allegations were also displayed on mobile billboards driven around Nottingham Forest’s stadium, the City Ground, on two match days. The YouTube channel, X account and website were all later taken down.

Sherborne said that the publications were designed to “give the false impression” that the campaign was a “grass-roots” initiative led by Forest fans relating to the club’s ownership.

Marinakis, who did not attend Thursday’s hearing, began the legal action in April and is also suing Amani Swiss (Cyprus) Limited, a company of which Karipidis is president; and Israeli national Ari Harow, and his company, Sheyaan Consulting Limited.

Sherborne said that Harow was a political consultant and chief executive of Sheyaan Consulting, and was the former chief of staff to the Israeli prime minister, Benjamin Netanyahu.

He continued that the “smear” campaign “was organised, paid for and pursued by” Karipidis and Amani Swiss, with Harow and Sheyaan Consulting “participating in its creation and implementation”.

He added that the English courts were suitable to hear the claim as “the methods and the objective (the defendants) devised and pursued for their campaign were all quintessentially English”.

Matthew Hodson, for Karipidis, told the court that the publications were “procured or created by a US PR firm” named Harris Media, which was paid $25,000 (£19,350) but was not involved in the case.

But he said the social media campaign had “limited publication”, telling the court that it “fared pathetically” and that there was no evidence of “actual harm” to Marinakis’s reputation.

He told the court that the dispute stemmed from an incident at a match between Olympiacos and Aris, which Karipidis runs with her brother, Theodoros.

It was claimed that in the 2022-23 season, Marinakis approached Theodoros Karipidis to fix a “critical” game between the teams so that Olympiacos would win, but Karipidis refused and the game ended 2-2, with Olympiacos - who had won the league in the previous three seasons - finishing the season in third place.

Hodson said: “During the game, Mr Marinakis became so angry that, according to Ms Karipidis, he threatened that Theodoros ‘would not leave the field alive’ if Olympiacos lost.

“At the end of the game, Mr Marinakis then told Theodoros, ‘you are finished’ and ‘I will destroy you’. Thereafter, Mr Marinakis began a campaign of intimidation and interference with the lives and businesses of Ms Karipidis and her brother.”

The barrister continued that Marinakis “seeks to harass the defendants” and that Irini Karipidis and her family had suffered “very real criminal damage and arson” as a result.

He continued the claim was “wholly unexplained if not as revenge for the Aris [versus] Olympiacos game” and that the damages sought were “utterly disproportionate”.

He added that “this is a case in which the candle is not worth the wick” and had been launched “for the improper collateral purpose of beating the defendant over the head with vast sums of money and costs to punish [Ms Karipidis]”.

Hodson said that Harow introduced Irini Karipidis to Harris Media, which was paid by Amani Swiss, but that the case against the company was “almost non-existent” and it “merely loaned [Ms Karipidis] the money to pay” for the publications.

Ali Reza Sinai, for Harow and Sheyaan Consulting, also applied for the case to be thrown out, claiming that while there was “obviously bad blood” between Marinakis and Irini Karipidis, the allegations have “no real connection” with his clients.

The hearing before Richard Spearman KC, sitting as a deputy High Court judge, continues and follows a turbulent month for the Forest owner who was handed a five-match stadium ban for allegedly spitting towards match officials in a “flagrant display of disrespectful behaviour”. Marinakis claimed he was disposing of “phlegm” because of a hacking cigar cough.