The woman was replaced because her daughter worked as a legal secretary in the office of the Los Angeles district attorney Gil Garcetti. Mr Garcetti oversaw Mr Simpson's criminal prosecution, but the judge only learnt of the connection on Thursday through a letter from Mr Garcetti's office.
Her place was taken by an Asian computer programmer in his thirties, picked by lottery from four alternate jurors. The change has made the jury's racial make-up in the second Simpson trial still more dramatically different from that in the first.
Picked from the mostly white areas of West Los Angeles, around the Santa Monica court-house, it now has six women and six men. Nine are white, one Hispanic, one Asian, and one a Jamaican-born man of black and Asian parentage.
The criminal jury, which unanimously found Mr Simpson not guilty, had nine black members, mostly women. Under Californian law, the jury must now start from scratch.
Judge Fujisaki told them only that a juror had been dismissed for "legal causes". "You are instructed to disregard and put out of your mind all past deliberations and begin deliberating anew," he said.
Mr Simpson is being sued for wrongful death and "battery" by the families and estates of his former wife, Nicole Brown Simpson, and her friend Ronald Goldman, found murdered in June 1994.
Jurors have to decide whether it is "more likely than not" that he killed them. The plaintiffs' attorneys argued in a closed-door meeting for keeping the woman on the panel.
Yesterday, Daniel Petrocelli, the lawyer for Mr Goldman's father, asked the judge to sequester the jury for the remainder of the trial rather than have them return nightly to their homes.
"These jurors are going to be subjected to an extraordinary blast of publicity about their deliberations," Mr Petrocelli said. "I'm very concerned about this. I don't want a mistrial."
Judge Fujisaki refused, saying he had no authority for sequestration in a civil case. "I will not sequester this jury," he said. Network anchors have descended in force to Camp OJ by the sea, as the media village outside the Santa Monica court- house is known, Until yesterday they had little news to go on.
As the jurors began again yesterday, a guessing game that began on Tuesday was launched anew. In requests to the judge, the jurors' interest to date had seemed to turn on defence claims that police massaged or mishandled the pivotal blood evidence.
They asked to see enlarged photographs of DNA test results and watched a police inventory video of Mr Simpson's bedroom which shows no socks on his floor. The defence alleges that the socks, with splashes of blood, were planted; police investigators say they were retrieved earlier .
In another sign of mounting pressure on jury members, Los Angeles sheriff's deputies raided the home of Brenda Moran, a juror from the criminal trial.
Ms Moran had signed a letter sent to two civil jurors recommending the services of a publicity agent. The letter, signed by a second juror, said, in effect: "We respect your verdict and look forward to meeting you ... if you need someone to talk to, don't hesitate to call us," her attorney said. It was supposed to be sent after the trial, Ms Moran claimed yesterday.