WASHINGTON (AP) _ A new book on the 1969 Chappaquiddick case alleges that Sen. Edward M. Kennedy may have staged the fatal bridge accident to cover up an earlier car wreck that same night.

In a book released today to Washington media, author Kenneth Kappel said ''previously overlooked'' evidence indicates that Kennedy may have pushed his black Oldsmobile off the Dyke Bridge to cover up an earlier accident and to conceal his own drunken state.

Kennedy's Senate office had no immediate reaction to the book.

Titled ''Chappaquiddick Revealed,'' the book raises new allegations about the events of July 18, 1969, when the Massachusetts Democrat and 28-year-old Mary Jo Kopechne were involved in an accident that claimed Kopechne's life.

The book is published by Shapolsky Publishers Inc., a small New York firm.

Gwen and Joseph Kopechne, the victim's parents, released a statement calling for Kennedy to respond.

''We believe that Mr. Kappel's book does present new evidence, and that it is worthy of serious attention,'' the Kopechnes said.

Kappel's book contends the car driven by Kennedy with Ms. Kopechne in the passenger seat was involved in an accident on dry land on Chappaquiddick Island. According to Kappel, the car rolled over onto its roof. The author theorized that Kennedy believed Kopechne was killed in the accident, got help in righting the car and then pushed it off the Dyke Bridge.

Kappel's book said all of the damage to the car could not have been caused by the plummet off the wooden bridge, and that bloodstains found on Ms. Kopechne's blouse were dried stains from a previous accident. Also, he said a dangling left side-view mirror could indicate a common technique in pushing cars into water: tying the mirror to the steering wheel to steady the vehicle.