Civil rights leaders are demanding that the Rev. Ralph David Abernathy retract implications in his new book that the Rev. Martin Luther King Jr. had sexual encounters with women on the night before he was killed.

A Memphis, Tenn., woman said in an interview published Friday that she was with Abernathy and King that night, and she disputed part of the account in Abernathy's autobiography, "And The Walls Came Tumbling Down."In his book, published this month, King's onetime top aide says King spent parts of the night before his death alone with two different women and physically fought with a third.

Abernathy wrote that he awoke from a nap in a woman's living room after a late-night dinner to see King and the woman emerge from a bedroom. Adjua Abi Naantaanbuu told The Commercial Appeal in Memphis that she was host of the dinner and that she and her sister talked with King and another aide in the living room while Abernathy, who "had too many" drinks, slept on her bed.

In an interview published Friday in The Atlanta Journal-Constitution, Abernathy rejected suggestions by some of the civil rights leaders that two strokes and brain surgery might have impaired his memory. "I am most surprised anybody would think I'm mentally incompetent," Abernathy said.

Abernathy has said that he did not include passages about King's extramarital affairs out of malice, but felt he needed to address the issue since it had been discussed in previous biographies of the Nobel Peace Prize winner.

"I loved Martin Luther King more than a brother. I would never do it to injure him," Abernathy said.

A coalition of black leaders including Jesse Jackson and Andrew Young said Thursday they objected to the controversial passages and doubted that Abernathy wrote them. A spokesman for the book's publisher replied that the whole book was written solely by the Atlanta minister.

The group's statement concluded that "the Memphis section" of Abernathy's book was so out of character with Abernathy's life and previous statements that it must have been "put into your mouth by others who needed a sensational story to sell books and slander the name of your martyred brother."

Steve Sorrentino, a spokesman for Harper & Row in New York, said the allegations are untrue.