James Stieglitz, a relative of renowned American artist Georgia O'Keeffe, was charged in an arrest warrant yesterday with violating copyright laws in connection with reproduction of O'Keeffe's works.

Stieglitz, who lives near Middleburg, Va., is also under investigation by the FBI for allegedly making available for sale fraudulent lithographs supposedly signed by the artist, who is 93 years old and lives in New Mexico. The FBI estimates that the sale could gross $18 million.

O'Keeffe, who is Stieglitz's great-aunt, says she has neither authorized nor signed the works, which are apparently photographic reproductions of her paintings.

Stieglitz, 34, denies that he has been in any way involved in the "publication, signing or sale" of any of O'Keeffe's works. By late last night, he had not been served with the arrest warrant charging the copyright law violation, which was sworn out yesterday afternoon in Manhattan by U.S. Magistrate D.V. Washington.

Some of the prints were being offered for sale this weekend at a minimun of $3,000 each in the Georgetown home of Robert Yowell, a holistic chiropractor who said Friday that his commission on the sales "will be used to build a holistic health center."

Informed yesterday that the prints were alleged to be bogus, Yowell expressed surprise and denied any knowledge of this. "I've got a fortune tied up in this thing and you're kind of shooting me in the head," Yowell said. "I can't tell you how much stock I've given Jim for this, not to mention $30,000 or $40,000 cash for travel expenses. He told me that O'Keeffe was very interested in holistic medicine, and we were going to call it the Georgia O'Keeffe Holistic Health Center."

"I have never made lithographs or prints of any type," O'Keeffe told The Washington Post by phone from her home in New Mexico. "If my signature is on anything like that it's a forgery."

"The poor, poor lady," said FBI agent Tom McShane, head of the Bureau's stolen art division in New York, which has been conducting an undercover investigation of the matter since April 7. "She's 93 and trying to live out her life."

The FBI claims that Stieglitz -- the grandson of a brother of O'Keeffe's late husband, photographer Alfred Stieglitz -- allegedly had printed and signed 250 portfolios, each containing 25 reproductions of O'Keeffe's work. According to the FBI, Stieglitz, who lives near Middleburg in Loudoun County, also is suspected of forging documents from art appraisers and his great-aunt to authenticate the material. The FBI also claims that Stieglitz has approached the heads of several charitable organizations to act as intermediaries for the sale of the forged art work.

"As far as we know, none of the individuals approached knows that the works are forged," Juan Hamilton, an associate of O'Keeffe, said this weekend.

On Sunday, Stieglitz said the only O'Keeffe portfolio he personally knows about is one that he says was stolen from his home this month. "I know that Dr. Yowell is selling porfolios," Stieglitz said. "Where they came from I don't know. You're spending too much time listening to a senile nonagenarian. I can't stand her art," he said. "I didn't publish any of her work."

Last Thursday, a quarter-page ad appeared in the weekly Loudoun Times Mirror, offering a $5,000 reward "for the arrest or conviction of person or persons who have stolen a set of Georgia O'Keeffe [sic] lithographs."

Loudoun County investigating officer Greg Stocks took the burglary report from James Stieglitz on April 13.

"Stieglitz told me he was a medical doctor," Stocks said Saturday. "He said the art had been done by his aunt, and he showed me a letter from an art gallery in New York with an appraisal that said in five years these things would be worth $10,000 per print."

A copy of this appraisal letter made available by Yowell yesterday. The letterhead reads "Casper Fine Arts & Appraisers, 501 East 87th Street, New York City" and is dated November 39 [sic], 1980." It was sent to a "Mr. Ido Ben Porat is an associate of James Stieglitz, according to Robert Yowell's wife, Donna. Although the letterhead includes a phone number, the business is not listed with the New York City phone company.The listing with the phone company for Lawrence Casper, whose signature appears on the appraisal, is different from the one on the letterhead.

Reached late last night, Casper defended his validation of the prints, claiming, "I know the source that produced them and the chain they followed from her."

Informed that a warrant had been issued for Stieglitz's arrest and that the FBI was investigating the validity of the lithographs, Casper responded, "that's interesting, check with me tomorrow," and hung up.

According to Loudoun County investigator Stocks, Stieglitz said, "the set of prints had been stolen from a house that he and Robert Yowell had bought from [former Redskins coach] Jack Pardee."

"I own this house alone," Stieglitz said Sunday. "Maybe I own it with the bank. I owe quite a bit of money on the mortgage."

Reached at the office of the San Diego Chargers on Monday, Pardee disagreed: "Stieglitz is renting the house from me.We have a lease agreement. He told me he was in the art business."

Stieglitz also said he breeds attack dogs and horses, was a Green Beret, and claimed he has a degree from the medical school at the University of Wisconsin, where he said he got his undergraduate degree. The FBI said that Stieglitz definitely is not a medical doctor, and that he also has worked as a commodities broker. Stieglitz said "I have never been a commodites broker. I am a very active customer of Merrill Lynch."

The University of Wisconsin Medical School has "no records" on James Stieglitz, according to Florence Waisman of the register's office. He did receive a BA in Medical Science from the undergraduate college on June 3, 1972.

"There was something very strange about the guy," Stocks said. "One day when I went out to the house he was dressed up in a military uniform, and he told me he was a general. I had talked to some people in Middleburg who said that Pardee was only renting the house [to Stieglitz], although there was all kinds of work going on there -- walls being ripped out -- and that didn't fit with being a renter. The guy reeks of money. He drives a $30,000 Porsche."

Stieglitz denied that he was in uniform or had said he was a general. "I think I'm a little young for that," he said. As for driving a Porche he said, "Sometimes -- when it's not in the repair shop."

"One day I was in Middleburg and he was eating at The Red Fox Inn," Stocks said. "His car was outside in a no-parking zone, and he had a card in the window that said 'Physician On Call.'"

On April 24, the day after the quarter-page ad ran in The Loudoun Times Mirror, a quarter-page ad appeared in the biweekly Georgetowner announcing: AT LAST! In Her 93rd [sic] Year The Lithographs Of GEORGIA O'KEEFE [sic]

The ad listed the phone number of Robert Yowell.

"We are making appointments to see the portfolios," Donna Yowell said on the phone Friday, before being informed that the lithographs were allegedly forged. "These are portfolios of 25 signed images. There is an edition of 250 portfolios, with an additional 40 sets of artist's proofs. . . . eThe portfolios were published by J.K. Fine Arts in New York City."

There is no phone listed for J.K. Fine Arts in Manhattan. Nor is there a listing for Joseph Klineman of Manhattan, whom Donna Yowell says she was told made the lithographs.

On Saturday, Robert Yowell said, "The portfolios are from James Stieglitz. He doesn't want any publicity for this. He's very protective of his aunt." Yesterday Donna Yowell showed one of the portfolios to this reporter at a Georgetown townhouse she said the couple had rented a few weeks ago as a base of operations for selling the prints. All but one of the poster-sized images were embossed with the corporate seal of the Jean Ann Stieglitz Fund, "in memory of Jim's sister," Donna Yowell said. A few of the prints were hanging framed on the white walls of the house.

Suspicion about fraudulent O'Keeffe lithographs began last November, when a few men walked into the prestigious Knoedler Gallery on Madison Avenue in New York and told employee Sherry Morse that they represented an anonymous relative of O'Keeffe who had been authorized to publish a signed, limited-edition portfolio of her work. Morse was dubious, and called this reporter, who knows O'Keeffe. O'Keeffe told this reporter that no such portfolio existed. Informed of this, Morse said she would have no dealings with the men, although she refused to reveal their identities to this reporter.

According to the FBI, Stieglitz allegedly has been attempting to move the prints in various ways. At the end of last year, he allegedly contacted a director of the Association of Retarded Citizens in Milwaukee, offering a portfolio and a deed of gift from O'Keeffe.

"We have received a gift and we were offered a second by James Stieglitz," said Constance Pukaite, the director. "There are some rather bizarre events attached with this that I'd rather not discuss. I'm aware of the FBI investigation."

Stieglitz was in New York at the time, according to O'Keeffe's attorney Gerald Dickler, staying at the Mayfair Regency Hotel. He had checked into the hotel, where O'Keeffe is a regular guest, allegedly using a forged letter from O'Keeffe that claimed he was in town on business for O'Keeffe, setting up an O'Keeffe foundation. After Stieglitz had run up a $1,500 tab, Dickler said the hotel manager called him to question the letter, and then the manager asked Stieglitz to leave the hotel.

"This is very private information," said hotel manager Dario Mariotti. "We cannot discuss it on the phone."

Stieglitz said he has stayed at that hotel, but "obviously I would deny all the rest. I have given the Association of Retarded Citizens photographs of Alfred Stieglitz. I have a letter from their attorney, David A. Weber, acknowledging the gift. When do you think it's dated? December 31, 1980. I'm no dummy."

Weber acknowledged the letter yesterday, but added, "I don't want to comment on that any further."

At about the same time, an unidentified man approached the Marlboro Gallery in New York to offer O'Keeffe portfolios. He was turned away. About three weeks ago, according to Knoedler Gallery president Maury T. Leibovitz, "two men who claimed they were from The Rosenthal Art Company offered the gallery O'Keeffe lithographs." The men -- who were different from the ones who had visited in November -- were also turned away. There is no telephone listing for The Rosenthal Art Company in New York City.