A search warrant served at Michael Jackson's house the day after he died says family members told investigators they'd found heroin in the singer's room. But tests later showed the substance wasn't heroin, a person with knowledge of the results told The Associated Press.

The person was not authorized to speak with the media and requested anonymity.

The warrant unsealed yesterday showed that various drugs, including marijuana, the generic form of Valium and other sedatives were found in the singer's rented mansion.

A detective also indicated that Jackson's body showed signs of injections.

A second warrant served on the car of Dr. Conrad Murray, the focus of a manslaughter investigation, turned up some documents but no additional drugs.

JACKSON DOCTOR WON'T SEEK TO RAISE KIDS

Michael Jackson's longtime dermatologist does not plan to petition for a role in the upbringing of the singer's three children, his attorney said yesterday.

Mark Vincent Kaplan said Dr. Arnold Klein is satisfied that a judge appointed an attorney to oversee the interests of the singer's children, who range in age from 7 to 12.

Kaplan surprised many by saying Klein wanted a role in the children's lives during a court hearing earlier this month.

Jackson's mother, Katherine Jackson, was granted permanent guardianship of the children during the hearing as spelled out in the singer's 2002 will.

Klein's involvement in the case raised questions about whether the doctor could be the father of Jackson's two oldest children, a rumor fueled by tabloid reports and Klein's own cryptic answers when questioned on the matter.

ARBITER BACKS PIVEN IN CONTRACT DISPUTE

Score one for Jeremy Piven.

A professional arbiter has ruled Piven did not breach his contract with the Broadway producers of "Speed-the-Plow" when the actor abruptly left the revival of the David Mamet play last December.

At the time, Piven's doctor said Piven was suffering from mercury poisoning after eating too much sushi.

Results of the arbitration were released yesterday by Actors' Equity Association, which represents stage performers.

"I feel like all you can ask for in this life is to have your day in court and I had that," Piven said. "The facts were presented and it has been a really long journey for me. I am really happy that we can all move on and that all of the facts, and the medical facts, were heard. That the truth prevailed."

The "Speed-the-Plow" producers expressed disappointment, saying that while they respect the decision, "we strongly disagree with it."

Piven has wrapped filming season six of his HBO television series "Entourage," in which he plays agent Ari Gold, and he has just completed a lengthy tour promoting his latest movie, "The Goods."