Ronald Reagan's official biographer says the former president is "the most mysterious man I have ever confronted" and that even Nancy Reagan is bewildered by him.

The remarks, by prize-winning historian Edmund Morris, were made at a closed meeting last October at the White Burkett Miller Center of Public Affairs of the University of Virginia.They were published, apparently prematurely, in the organization's current newsletter.

"He is the most mysterious man I have ever confronted. It is impossible to understand him," Morris was quoted as saying.

Morris won the Pulitzer Prize and the American Book Award in 1980 for "The Rise of Theodore Roosevelt," the first volume in a projected three-volume biography of the 26th president.

He has been working on the Reagan biography since 1985, and it is expected to be published next year by Random House.

"I went through a period of a year or so of depression because I felt that with all my research, how come I can't understand the first thing about him?" Morris said of Reagan.

"He grew more puzzling the more I tried to study him. I only came out of this despair when I found out that everybody else who had ever known him, including his wife, is equally bewildered."

Kenneth W. Thompson, director of the Miller Center, said the writer took part in two sessions, one off the record and one on the record.

"I am afraid our people jumped the gun a little, because he was supposed to see both versions before there was any release of them," Thompson said. Robin Kuzen, editor of the newsletter, said the quoted remarks were made in the on-the-rec-ord session.

Morris' telephone in Washington was answered by a recording.

Bill Garber, Reagan's spokesman in Los Angeles, said the former president and his wife were out of town.

As part of the arrangement with the White House, Morris sat in on many closed Reagan meetings.

He has declined to give interviews, saying they were forbidden by his agreement with Reagan.

Morris said his interest was piqued when, watching television, he saw the "agony" on Reagan's face as he emerged from a museum at the Bergen-Belsen concentration camp during a visit to West Germany in 1985 that included a controversial stop at a cemetery in Bitburg. Among the thousands buried there were members of the Waffen SS, Hitler's elite troops.

He said deputy White House chief of staff Michael Deaver agreed to give him access to the White House and monthly interviews with Reagan.

"He had the guts to let somebody come in from outside, stare at him, read his mail, go off and talk to his children," he said. "Whatever you say about Ron Reagan, he has guts."

Morris is quoted as finding Reagan's personality "irresistible" and saying world leaders were "seduced by (his) extraordinary personal sweetness."

"Of course, I was seduced by it myself," he said. "What hindsight shows us is that after he has left the room, after he has left the White House, after he has left our national life and gone off to retirement, the charisma goes with him and we realize how seduced we were."

The newsletter writer said Morris also likened Reagan to a glacier.

"He's large and he's slabby and he's cold," Morris said. "But he has an inexorable, slow force which carves out this great valley in the landscape. Rocks shatter as he forces his way through them, and they end up on his back and they ride his back as he inches forward; eventually, they tumble off. And the glacier keeps growing and growing."