The judge in Michael Jackson's child abuse case intends to prevent more than 70 items seized from the singer's ranch being used against him in evidence.
The singer attended the first day of the pre-trial hearing
Judge Rodney Melville made the preliminary ruling at a pre-trial hearing in California.
Mr Jackson's lawyers told the hearing that police tried to search parts of his Neverland ranch not permitted by their warrant last November.
The 45-year-old singer has pleaded not guilty to 10 child abuse charges.
Judge Melville said out of 120 items of evidence Jackson's defence team wanted thrown out, he was inclined to disallow more than 70 from appearing at trial.
He said he would allow the trial jury to see only 34 pieces of evidence unless prosecutors and defence lawyers convinced him otherwise in written arguments.
"I am making this tentative ruling for the purpose of arguments and objections," Judge Melville told the court.
"It is my intent to suppress the remaining material."
Lawyers have until 3 September to submit their
arguments ahead of the next hearing in the case, scheduled for 16 September.
Police are known to have seized cameras, computers, documents, and video and audio tapes from Jackson's Neverland ranch in a raid in November 2003.
Items were also seized when police raided private investigator Brad Miller's office to retrieve videotaped interviews featuring the boy at the centre of the child molestation case.
Judge Melville's tentative rulings ended five days of hearings in Santa Maria, California.
Mr Jackson attended the first day of the five-day hearing on 16 August, with members of his family, dressed entirely in symbolic white.
He missed the remainder of the proceedings with the judge's permission.
The 45-year-old singer is scheduled to stand trial on 31 January.