SANTA MARIA — Michael Jackson’s defense attorneys hope to bring one of the singer’s alleged co-conspirators to the stand by seizing on an immunity grant prosecutors secretly gave him before Jackson’s molestation trial began.

In a motion released Thursday, the defense said prosecutors met with former Jackson employee Vincent Amen on Dec. 29, 2003, and granted him “use immunity” guaranteeing that his statements would not be used to prosecute him.

But prosecutors decided not to call Amen to the stand because his testimony did not support their case, the defense motion said.

“Much of what Mr. Amen told the government contradicted the statements of the (accuser’s) family and defeated circumstantial evidence inferences which the prosecutor has made,” the motion said. “As a whole, Mr. Amen’s statements were exculpatory.”

The defense says it plans to call Amen and asked Judge Rodney S. Melville for an order clarifying that the prosecution’s grant of “use immunity” still applies even though Amen would be testifying for the defense.

Amen is one of five Jackson associates alleged to have been involved in a conspiracy to hold his accuser’s family captive in order to get them to do a video praising Jackson.

Meanwhile, former Jackson attorney Mark Geragos was expected to testify today.

sued a warning Thursday calling for Geragos to appear after a Geragos associate asked that Geragos be allowed to reschedule because he was working on another trial.

Melville said Geragos would have to obey a defense subpoena just like other witnesses and ordered that he be ready to take the stand Friday morning.

Geragos, however, arrived at the courthouse Friday well in advance of the trial start time. He did not immediately take the stand because a witness called earlier was still testifying.

It was unclear what Geragos would testify about. He represented Jackson while the star was under investigation but was let go in April 2004.

In another motion released Thursday, prosecutors asked the judge not to admit evidence that the then-16-year-old sister of Jackson’s accuser had a “quasi-sexual” relationship with an employee at Jackson’s Neverland ranch while her family was staying there.

Prosecutors said Jackson’s attorneys plan to call Neverland employee Angel Vivanco, who was expected to testify that he had a relationship with the sister, to raise questions about her credibility.

The prosecution said that because Vivanco was an adult at the time of the relationship and the sister was a minor, “she was a victim of felonious sexual misconduct by a defense witness employed by the defendant.”

Prosecutors also said defense attorneys had failed to show why the alleged relationship was relevant.

Jackson, 46, is accused of molesting a 13-year-old boy in 2003, giving him wine and conspiring to hold the boy’s family captive to get them to rebut the documentary “Living With Michael Jackson,” in which Jackson said he let children sleep in his bed but it was innocent.

Also Thursday, David LeGrand, a Las Vegas lawyer who worked for Jackson, testified that men who took over Jackson’s management diverted nearly $1 million of the pop star’s money. LeGrand said he believed it was for their own benefit.

LeGrand was called in a defense effort to portray Jackson as a victim of a conspiracy by his associates — the same men the prosecution claims he conspired with to hold his accuser’s family captive.

Prosecutors have sought to show that Jackson had deep financial problems that motivated the conspiracy as he faced career damage from the documentary. The defense has tried to show that there was no captivity conspiracy and that the associates’ actions were for their own financial gain.

Under cross-examination Friday, Deputy District Attorney Gordon Auchincloss got LeGrand to acknowledge he didn’t know whether the money was owed to the two managers.

But LeGrand said he never saw any evidence that the money was owed to the men and that one of them was unhappy that LeGrand received records of the transaction.

On Thursday, Auchincloss elicited from LeGrand that at one point he offered the accuser’s mother $25,000 to remain a party to a complaint made about the “Living With Michael Jackson” documentary to Britain’s broadcast standards board.

LeGrand said the mother, who defense attorneys have portrayed as a con artist desperate for money, turned down the offer.