Daniel Schweimler reports: "The latest twist in a long-running and complicated tale"

John Peter Moore, who worked as Dali's personal secretary, was arrested along with his wife after a tip-off from an unnamed man who worked with them, Spanish state radio reported.

He was detained following a complaint by the Gala-Dali Foundation, which holds the rights to proceeds from sales of Dali's work.

Police said they had discovered a cache of what appeared to be forgeries of the artist's work after a search of Mr Moore's home, several art centres and a museum run by the couple in Dali's native Catalonia.

"Thousands of prints have been seized, many of which are signed by Dali and conveniently numbered, with some ready for sale at the price of 180,000 pesetas ($1,155) each," police said in a statement.

'I have all the real Dali I need'

Local reports suggest that as many as 10,000 allegedly forged lithographs had been seized.

Art experts were examining the works to determine whether they were authentic, police said.

However Mr Moore was quoted by the Efe news agency as saying: "I was Dali's assistant for 20 years and I don't need to do forgery, I have all the real Dali I need."

The surrealist at work

Dali met Mr Moore, a British citizen, in Rome in 1955 when Mr Moore was working for the film director Alexander Korda.

He had arranged to deliver money to Dali for the purchase of a portrait of actor Laurence Olivier as Richard III.

The pair immediately hit it off and Mr Moore became the painter's personal secretary.

The former aide, dubbed "Captain Moore", is reputed to be an expert on Dali and has put together an important collection of his works, including "The Apotheosis of the Dollar," which he sold to the Gala-Dali Foundation, and the artist's 1974 sketch of the Statue of the Liberty.

Salvador Dali's works have long been associated with fraud. Late in his life and after his death from heart failure in 1989 there was a string of alleged and actual forgeries of his paintings.

Blank canvases signed

The roots of the problem lie in the last five years of Dali's life, after he suffered severe burns in a fire. He became something of a recluse, and friends and the Spanish Government feared that he was being manipulated by his aides.

It was in particular alleged that the mustachioed painter was made to sign thousands of blank canvases, which led experts to question the authenticity of some of his later works.

Lee Catterall, author of The Great Dali Art Fraud and Other Deceptions, reported that according to Mr Moore's estimates, Dali signed some 350,000 blank sheets of paper at a rate of 1,800 autographs per hour.