Duvall is best known for Apocalypse Now

The Godfather star said: "Spielberg went down there recently and said, 'The best seven hours I ever spent was actually with Fidel Castro'."

Duvall asked on CBS if Spielberg would "consider building a little annexe on the Holocaust museum... to honour the dead Cubans that Castro killed".

The remark attributed to Spielberg was "totally false", his spokesman said.

Duvall, 73, is best-known for playing Tom Hagen in The Godfather II and the Napalm-loving Lieutenant Colonel Bill Kilgore in Apocalypse Now.

Cultural exchange

Spielberg was an executive producer of Deep Impact, in which Duvall played a veteran Nasa astronaut.

But the actor also told the 60 Minutes II programme he would never work for Spielberg's film studio, DreamWorks, again.

Of the contentious comment, Spielberg's spokesperson responded: "He never said it, or anything like it."

The director's four-day trip to Cuba in November 2002 was as part of a cultural exchange authorised by the US government, he said.

Spielberg held an eight-hour meeting with Castro during which they discussed cultural exchanges, history, the environment and the US trade embargo.