It is reported that Brendan Gleeson is to star opposite Joaquin Phoenix and Lady Gaga in the Joker sequel, Joker: Folie à Deux.
US entertainment website Deadline, which first reported the news of Gleeson's casting, said there are no details at present on the character he will play.
Production is due to begin in December for an October 2024 release.
The sequel sees Joker director Todd Phillips back behind the lens, co-writing the script with Scott Silver, who wrote the first film.
"Not much is known about the sequel, though insiders believe it will have musical elements and will also be set in Arkham Asylum, which is where the first film leaves off after Arthur Fleck (Phoenix) has been sent there," said Deadline.
Gleeson will next be seen opposite Colin Farrell in The Banshees of Inisherin, the new film from their In Bruges writer-director Martin McDonagh.
The dark comedy will have its world premiere at the Venice Film Festival on Monday 5 September and will open in Irish cinemas on Friday 21 October.
Farrell memorably portrayed The Penguin in Joker and is set for a spin-off series.
