LOS ANGELES -- Filmmaker Michael Moore is asking the Bush administration to end its investigation of his trip to Cuba.

Moore traveled to the island nation in March to get treatment for some ailing 9/11 rescue workers for a segment in his upcoming health care documentary, "Sicko."

In a letter to U.S. Treasury Secretary Henry Paulson, Moore said that the White House may have opened the investigation for political reasons.

Moore said that the Bush administration is "coming after" him because he's trying to help the people they "refuse" to help. But the filmmaker insisted that he has broken no laws and has nothing to hide.

Moore railed against the administration for their handling of Sept. 11 and the Iraq war in the documentary "Fahrenheit 9/11." When Moore accepted the Best Documentary Oscar for film, he openly criticized Bush -- and was met with a combination of cheers and jeers from those at the ceremony at Hollywood's Kodak Theater.

Regarding the scrutiny over "Sicko," Treasury officials said that they won't comment on Moore's letter, citing a policy against discussing specific investigations being conducted by Treasury's Office of Foreign Assets Control.

The agency enforces the trade embargo against Cuba.