LOS ANGELES — The stories were flying around eight years ago, when Arnold Schwarzenegger was in the midst of his unlikely attempt to unseat Gray Davis, the Democratic governor: Mr. Schwarzenegger, married to Maria Shriver, had fathered a child with a woman who worked at the couple’s Brentwood estate.

Mr. Schwarzenegger’s advisers had heard it. So had top aides to Mr. Davis, whom Mr. Schwarzenegger would go on to unseat. But in the closing days of what was a circus of a campaign, the rumors got pushed aside as Mr. Schwarzenegger dealt with a barrage of seemingly more credible allegations that he had groped and molested women during his years as a movie star, charges that Ms. Shriver battled back forcefully, contributing in large part to his victory.

In fact, Mr. Schwarzenegger acknowledged on Tuesday, he had fathered a child with a member of his household staff a few years before running for office, a secret that he said he hid from his wife and that aides said he kept from them. Through much of her pregnancy and for the eight years that Mr. Schwarzenegger served as one of the highest-profile governors in the nation, the woman continued to work in the couple’s home. Some of their friends, looking back, said they now believe the child was an occasional presence in the house in the gated community at the end of Mandeville Canyon Road.

That deception by Mr. Schwarzenegger ended Monday night when the governor, responding to an inquiry from The Los Angeles Times, released a statement acknowledging his child. Ms. Shriver — his wife of 25 years, a former television news correspondent and a member of the Kennedy family — issued her own statement Tuesday reflecting what her friends described as the devastating and utterly shocking collapse of a marriage that had captured national attention. Ms. Shriver had moved out of the house and into a Beverly Hills hotel earlier this year.