SEATTLE (AP) _ A holdout juror at the center of a controversy over the verdict in the nation's first death-by-tampering trial has admitted that she herself was involved in an earlier tampering case, according to a report published today.

Juror Laurel Holliday told the Seattle Times that she sued after she bit into a cracker that contained an aspirin substitute and settled the case out of court only two months before she became a juror in the cyanide case.

She said she never told court officers of her own case before she became involved in the trial of Stella Nickell, who was convicted Monday of killing her husband and another person with tainted Extra-Strength Excedrin.

Ms. Holliday, the focus of a jury tampering investigation being pushed by Mrs. Nickell's attorney, has admitted to being the holdout juror who broke an 11-1 deadlock on Monday when she changed her vote.

Mrs. Nickell, 44, of Auburn, was convicted on five counts of product tampering and faces a June 17 sentencing in the deaths of her husband, Bruce Nickell, 52, and Susan Katherine Snow, 40, of Auburn. She faces life imprisonment.

U.S. District Judge William Dwyer has already ordered the panel to come back to court Friday, at the request of the defense, to determine whether the verdict was tainted by outside influece.

Ms. Holliday had told Dwyer that she got a telephone call last Friday, while the jury was deliberating, from an anonymous caller who told her that Mrs. Nickell had failed an FBI lie detector test.

She told Dwyer the call would not affect her vote and Dwyer allowed her to remain on the jury until it reached a verdict.

Mrs. Nickell poisoned her husband to collect his insurance, then put tainted painkillers on a store shelf to divert suspicion from herself, according to the prosecution. She faces a maximum penalty of life in prison.

In an interview in today's Seattle Post-Intelligencer, Ms. Holliday, confirmed that she was the holdout in a series of 11-1 votes during five days of deliberations, as indicated earlier by lawyers and other jurors.

The Times said that in her own tampering incident, Ms. Holliday told police her mouth started burning after eating a cracker on July 31, 1986. She found half of an ibuprofen pill in the uneaten portion of the cracker, called poison control and vomited, she said.

Ibuprofen is an aspirin substitute commonly used in over-the-counter pain relievers. A year later, Ms. Holliday sued the manufacturer of Goldfish crackers, Pepperidge Farm Inc. The case was assigned to arbitration and settled out of court for $500.

There were no witnesses and Pepperidge Farm attorneys questioned whether the event ever took place.

Ms. Holliday said she didn't tell the judge or attorneys about the incident during juror screening because she didn't think it was important.

In her interview with the Post-Intelligencer, Ms. Holliday denied defense attorney Thomas Hillier II's suggestions that she might have fabricated the report to be excused from deliberations or that another juror might have made the call.

''He is playing his last cards in a desperate attempt to save his client,'' Ms. Holliday said.

Ms. Holliday, a real estate agent, told Dwyer before the verdict Monday that a female voice she did not recognize told her Friday night that Mrs. Nickell had failed an FBI lie-detector test - a fact that had not been admitted as evidence in court.

Dwyer let her stay on the jury after she said the call wouldn't influence her deliberations, and Hillier concurred at the time.

But on Tuesday, after the verdict and learning about the 11-1 votes, Hillier filed a motion asking for permission to question the 12 jurors individually.

And on Wednesday, Dwyer said ''The court is required by law to investigate one way or the other'' whether there was jury tampering. ''It cannot let the matter sit.''

However, he emphasized that he was ''not suggesting in the slightest any misconduct by any juror.''

He told Hillier and assistant U.S. attorney Joanne Maida to submit questions to him. Dwyer said he would question the jurors under oath.

In the newspaper interview, Ms. Holliday expressed skepticism that the anonymous caller could have been another juror.

''I really resent the implication about the truth of the other jurors,'' she said. ''Hundreds of people knew who the jurors were, and my name happens to be in the (telephone) book.''

Names of the jurors were broadcast and published only after the trial but were given in court during jury selection and were available from the court clerk during the trial.

Ms. Holliday said she had no need to fabricate the report because had she wanted to be excused from the panel, she said, ''I could have called in sick.''