Attorneys in Michael Jackson's death received two key rulings on Tuesday when a judge kept in place a January criminal hearing for a doctor who supplied the pop star's medications, while his father lost a challenge to the estate.

A Los Angeles judge kept a January 4 start date for a preliminary hearing to determine if there is enough evidence for Dr. Conrad Murray to stand trial on a charge of involuntary manslaughter in Jackson's death.

The "Thriller" singer died in June 2009 from an overdose of prescription drugs, principally the powerful anesthetic propofol. Murray has admitted giving Jackson propofol as a sleep aid, but has pleaded not guilty to involuntary manslaughter.

In a separate matter in the 2nd District Court of Appeal, a three-judge panel unanimously ruled the singer's father, Joe Jackson, was not entitled to a court hearing to challenge the status of two men now in charge of Jackson's multimillion dollar estate.

At stake for Joe Jackson, 81, was a chance to participate in revenues earned by his son's estate.

Forbes magazine on Monday named Michael Jackson the top-earning celebrity of the year with revenues of $275 million pouring in from record sales, licensing and other business deals.

According to his will, Michael Jackson's estate benefits his three children, his mother and various charities. The estate is currently overseen by Los Angeles attorney John Branca and music executive John McClain.