Bert Stern says the photos, taken on assignment for Vogue magazine in July 1962, are worth more than $100,000 each.
He says they were in a series of "unique and irreplaceable images" of the movie star taken at Los Angeles' Bel Air Hotel six weeks before she was found dead from an overdose of drugs. That series was called "The Last Sitting."
The photos show Monroe, the star of "Gentlemen Prefer Blondes" and other movies, in various gently erotic poses behind a piece of transparent white gauzy fabric. The shots were recreated by Stern in a February 2008 photo session with Lindsay Lohan.
The New York photographer says in papers filed in Manhattan state Supreme Court that he lent the Monroe pictures to Eros magazine, a defunct 1960s quarterly, but they were not returned within a few months as expected. He says the photos were stolen.
Stern's lawyer, Stephen Weingrad, says his client learned the photos were being held by Michael Weiss of Mount Kisco, N.Y., and Donald Penny of Briarcliff Manor, N.Y., when they contacted him a few months ago and offered "to do a deal."
The men gave Stern two of the photos so he could authenticate them, but they said he would have to pay for the others, Weingrad said.
He said that after negotiations broke down because the men were too "greedy," Stern requested the return of the other pictures. They refused, so he sued, Weingrad said.
Stern's lawsuit accuses Weiss and Penny of unlawful possession of his property and unjust enrichment. Stern says he wants at least $700,000 for the value of the photographs and $1 million in punitive damages and legal fees.
A man who answered the telephone in Weiss' photography studio in Mount Kisco on Thursday said he would relay a call for comment, but the call wasn't immediately returned. A telephone message left for Penny at his home also wasn't immediately returned.
Eros, a magazine named for the Greek god of love, was published by Ralph Ginzburg, who died in July 2006 at 76. It dealt with sexual history, art, politics and literature and published only four issues.
Because of Eros' explicit content, Ginzburg was convicted in Philadelphia on federal obscenity charges in 1963. After the Supreme Court upheld the conviction in 1966, he was sentenced to five years in prison but served eight months.