Published Saturday, 24 November 2012
Prince William and Kate were in the south of France when the snaps were taken. (© Getty)
Michael O'Kane had been suspended from his role in September while an internal investigation was carried out into the paper's decision to publish pictures of Kate Middleton and Prince William sunbathing on a private holiday in France.
Media tycoon Richard Desmond, whose Northern and Shell group co-owns the newspaper with the Irish-based Independent News and Media, had threatened to shut the Dublin operation down.
The pictures featured under the headline "Angry Kate to sue over mag snaps" and did not appear in the Northern Ireland edition of the paper.
In a statement on Saturday, the Irish Daily Star said: "As a result of the publication on 15 September 2012, issues arose with the shareholders of Independent Star Limited.
"Having considered those issues in tandem with Mr O'Kane, it is Mr O'Kane's decision to resign as editor of the Irish Daily Star, effective immediately."
Independent News and Media said Mr O'Kane acted at all times in a highly professional and appropriate manner and in the best interests of the newspaper.
Furthermore, he followed all editorial policies and guidelines, the company said.
"Independent Star Limited thanks Michael O'Kane for his valued service and wishes him the very best in the next chapter of his career in the media, which we are certain will be long and fruitful," the statement said.
The photographs of the Royal couple were taken during their holiday in the south of France.
They were originally published in French magazine Closer, prompting the Duke and Duchess of Cambridge to launch legal action for breach of privacy.
Chi, an Italian gossip magazine, has also published a 26-page spread with the topless photos featuring Kate.
© UTV News