Boulder, Colo. ? An ex-detective who wrote a book accusing John and Patsy Ramsey of killing their daughter will pay the couple an undisclosed sum to settle their $80 million libel lawsuit.

Former police Det. Steve Thomas, co-author Don Davis and publisher St. Martin’s Press are participating in the settlement, Ramsey attorney L. Lin Wood said Tuesday. He would not say how the three will divide the payment.

The Ramseys filed the civil libel and defamation lawsuit in March 2001, accusing Thomas of making false accusations in the book “JonBenet: Inside the Ramsey Murder Investigation” and in television interviews promoting it.

Thomas had theorized that Patsy Ramsey killed her 6-year-old daughter and then tried to make it look like a botched kidnapping. Thomas accused John Ramsey of participating in the cover-up.

“They sued this case as a matter of principle,” Wood said. “A man wrote a book accusing Patsy of murder, and John of covering it up, and profited off a child’s death. And win, lose or draw, they were not going to tolerate it.”

Thomas’ attorneys, Daniel Petrocelli and Chuck Diamond of Los Angeles, did not return calls seeking comment.

No one has been charged in the Dec. 26, 1996, killing. Four defamation cases related to JonBenet’s death are still pending.