Nottingham Forest owner Evangelos Marinakis has launched a libel lawsuit against Premier League rivals Crystal Palace at London’s High Court, with reports suggesting the case centres on a controversial banner displayed by Palace supporters last season.

Greek shipping magnate Evangelos Marinakis filed the legal action on Monday against CPFC Limited and “Persons Unknown”, according to reports. The lawsuit is understood to relate to a provocative banner displayed during Crystal Palace’s home match against Nottingham Forest last August.

Marinakis became a target of criticism from Palace supporters after the London club were relegated from that season’s Europa League to the Conference League for breaching UEFA’s multi-club ownership regulations. Nottingham Forest subsequently took Palace’s place in the second-tier European competition.

The banner depicted Marinakis appearing to hold a gun to the head of Morgan Gibbs-White, accompanied by a speech bubble stating: “Mr Marinakis is not involved in blackmail, match-fixing, drug trafficking or corruption.”

Marinakis, who took ownership of Nottingham Forest in 2017, also owns Greek club Olympiacos. He has repeatedly denied allegations relating to match-fixing, corruption and other illicit activities.

Neither Marinakis’ lawyers nor Crystal Palace immediately responded to requests for comment regarding the lawsuit filed on Monday.