Judge Michael Pastor went to Sony Pictures Studios last week to view footage of Jackson preparing for a series of comeback concerts, but he said it could be commercially sensitive for Sony and was of no use to the trial.

Sony had sought to quash a subpoena seeking portions of the rehearsal footage not included in the film "This is It" to be used at the trial of Jackson's doctor Conrad Murray, who faces trial for manslaughter in September.

Pastor ruled that Sony's appeal was "meritorious," saying the material he had seen was "extremely valuable to Sony" and would "result in serious financial consequences" if released.

Prosecutors say the footage of Jackson rehearsing before his planned "This is It" series of concerts in London show him creatively engaged and in good health, while the defense argued against showing the images.

The judge said he spent several hours watching some of the footage, including Jackson rehearsing "The Way You Make Me Feel" on June 23, 2009, and "Earth Song" the following day -- the day before he died.

"As far as I'm concerned, it was a waste of my time to go over there," said the judge at the Los Angeles Superior Court.

One of Murray's lawyers, J. Michael Flanagan, said Jackson was "very talented...even on his bad days," but said the released footage would not be a fair representation of his condition in the days preceding his death.

Jackson, whose career had been hobbled by child sex abuse allegations, died on June 25, 2009 at the age of 50, as he prepared for the comeback concerts at London's O2 arena.

Prosecutors say he died as a result of an overdose of the powerful sedative propofol, which Murray was in charge of administering to help Jackson with his insomnia.

Murray's defense is expected to argue that Jackson gave himself an excessive dose of the drug while Murray was out of the room at the singer's mansion in the affluent Holmby Hills neighborhood west of Los Angeles.

Copyright APP (Associated Press of Pakistan), 2011

Copyright AFP (Agence France-Presse), 2011