Michael Moore says broke no laws with Cuba trip

Moore spokesman Chris Lehane declined comment on the exact events that took place in Cuba during the filmmaker's visit. But he did say the director brought with him some "9/11 heroes who had serious health problems."

"People will be very surprised and provoked as to what motivated the trip and actually transpired in Cuba," Lehane said. He added that Moore chose to post the letter on Daily Kos because that site "has been leading the fight for real reforms ... which is exactly what Michael does with his films."

The Weinstein Co., which is backing "SiCKO," said it hired high-profile Washington attorney David Boies to represent the film and brought on two New York publicity firms.

"SiCKO" is to premiere at France's Cannes film festival this month and in U.S. cinemas on June 29. Health care groups and U.S. politicians have already given reactions supporting and attacking Moore over the movie.

The storm of publicity and controversy is reminiscent of the lead-up to "Fahrenheit 9/11," which became the top-grossing political documentary of all time, raking in roughly $222 million at worldwide box offices.