Mr Moore, who worked with Dali for two decades and oversaw his lucrative move into mass production in the 1950s, was held by Spanish police on Tuesday in Cadaques, the Catalan fishing village where the artist lived until his death in 1989. Police also seized thousands of supposed Salvador Dali lithographs from tourist shops and art galleries in and around the village.
Forgeries worth more than $3bn (pounds 1.9bn) have been made from Dali's prints over the years, but Mr Moore, who lives in an opulent seaside mansion in Cadaques, has never before been implicated.
Officers are believed to have acted on a tip-off from one of his former employees, who is being questioned about another case. Mr Moore was released on police bail within hours of his arrest, but was required to make a statement yesterday.
Twenty officers searched his home, which has mirrored windows and a drawing room adorned with tiger skins, stuffed swans and rhino horns. His taste for the exotic includes keeping three ocelots - South American wild cats - as pets.
Mr Moore, who grew up in Co Cork, Ireland, and styles himself "Captain Moore" after an early career in the army, said before his arrest that the police investigation was based on "envy". "I worked with Dali for 20 years and I don't need to do a forgery," he said. "I have all the real Dali I need."
Mr Moore was working for the film director Alexander Korda in Rome in 1955 when he first met Dali. Korda had commissioned a portrait of Laurence Olivier from Dali, and Mr Moore arranged to deliver payment for it to the artist. The two men hit it off.
The move into mass production of Dali's works saw the artist sign an estimated 350,000 blank lithograph laminates during his final years, when he was sick and weak.
Mr Moore said in an interview a few years ago that his first advice to Dali was that he should paint on smaller canvases: "He only painted one or two paintings a year,. There wasn't much you could do with that. I suggested that he make graphics, lithographs, bedsocks, shoes, socks, ties ... anything commerciable."