Jackson didn't make it to the courthouse Tuesday morning. Instead, his driver took him to Marian Medical Center for treatment. The development delayed jury selection a week.
Merrill said Jackson is expected to recover fully. The singer is in stable condition and is being given fluids intraveinously.
A spokeswoman for the hospital said no additional information on the singer's condition would be given, due to his medical privacy. The singer's brother, Randy Jackson, told reporters that Jackson will spend the night in the hospital, reports CBS News Correspondent Vince Gonzales.
Judge Rodney Melville told prospective jurors that Jackson had the flu and that jury selection would resume Feb. 22. Lawyers were expected back in court Tuesday to discuss unspecified motions.
CBS News Correspondent Vince Gonzales reports Jackson was apparently feeling ill last night as he left court. This morning he felt even worse.
The judge made the initial announcement 15 minutes after Jackson was scheduled to appear in court at 8:30 a.m.
"Notice anything unusual? Mr. Jackson's not here," the judge said. He then told the court that that Jackson had been taken to the hospital.
The judge said later that Jackson's doctor had informed him that Jackson "is very ill with the flu."
The doctor informed the judge that Jackson would be ill for three to four days.
The judge told the jurors that they could not proceed without Jackson and that it would be a mistake to have everyone come back Friday. Since next Monday is a holiday, he ordered the proceedings to reconvene Tuesday, Feb. 22.
Jackson's illness comes one after questioning of prospective jurors got under way. Jackson's lawyers announced they may call Elizabeth Taylor, Jay Leno, Quincy Jones and Kobe Bryant to the witness stand.
The list of possible witnesses sounded like. But Melville dimmed that prospect, saying not all of the celebrities would necessarily testify.
Attorneys are in the process of selecting 12 jurors and eight alternates who will decide whether Jackson molested a teenage cancer patient at his Neverland Ranch and plied the youth with alcohol.
During Monday's proceedings, Jackson smiled and nodded at potential jurors. At one point he picked roughly at a fingernail, and later wrapped it in a napkin.
Names of defense and prosecution witnesses were revealed to prospective jurors Monday so attorneys could find out if any of the more than 240 members of the pool had associations that may be important in jury selection.
Defense attorney Thomas Mesereau Jr. also named two of Jackson's children, Paris and Prince Michael. Possible prosecution witnesses included Debbie Rowe, their mother.
Other possible witnesses included Stevie Wonder, Diana Ross, Chris Tucker, former child actor Corey Feldman, Backstreet Boy Nick Carter and younger brother Aaron, CBS News correspondent Ed Bradley, CNN's Larry King, Fox broadcaster Rita Cosby, New Age guru Deepak Chopra, psychic Uri Geller, illusionist David Blaine, Las Vegas tycoon Steve Wynn and relatives of the late Marlon Brando.
Prosecutors also listed the family of a boy involved in 1993 molestation allegations against Jackson. The judge has not yet ruled whether that incident can be mentioned in the trial. The accuser received a multimillion-dollar settlement and no criminal charges were filed.
Both sides listed former Jackson attorney Mark Geragos, and the defense list included Jackson's chief prosecutor, District Attorney Tom Sneddon.