NEW YORK (AP) _ A document dealer was arrested Monday on charges he forged papers supposedly proving President Kennedy had an affair with Marilyn Monroe.

Lawrence Cusack III was charged with mail and wire fraud.

Court papers said Cusack defrauded dozens of investors around the country of up to $7 million by selling them ownership shares of letters and notes purportedly written by Kennedy, Robert Kennedy and Miss Monroe.

He provided author Seymour Hersh with documents purportedly showing that Kennedy bought Miss Monroe's silence about the alleged affair by setting up a trust for her mother.

The documents initially formed the basis for a chapter in Hersh's book ``The Dark Side of Camelot,'' but Hersh deleted the chapter before publication last year after their authenticity was challenged.

ABC News, which was producing a documentary based in part on Cusack's papers, hired experts who concluded they were forgeries.

Cusack claimed to have found 700 documents relating to the Kennedy family, Miss Monroe and Chicago mob boss Sam Giancana in the files of his father, Lawrence Cusack, a lawyer who died in 1985.

Among the items that Cusack is accused of selling were a signed copy of Miss Monroe's will for $145,000 and a document written by Kennedy for $55,000.

Postal Inspector John G. Feiter said in court papers that Cusack admitted forging the documents.

Feiter also said he obtained a notebook of Cusack's that contains ``what appear to be practice signatures of other historical figures, namely, George Washington, Thomas Jefferson and Andrew Jackson.''

Cusack was arrested at his home in Fairfield, Conn. He could get up to five years in prison and $250,000 in fines.

Calls to his lawyer, Thomas Sargent, were not immediately returned.