Michael Jackson's drug intake and medical reports may never be made public thanks to an extraordinary court battle - The News Of The World can reveal.

Lawyers for MJ's estate want to stop Joe Jackson, 81, from getting his hands on reports including the singer's autopsy, toxicology probe, doctor's notes and UCLA hospital records in the final few hours of his life.

They have filed a court motion blocking Joe and his legal team from pulling public records to show his family the exact causes of Jacko's death.

Last week we showed the world the paperwork where coroners ruled Jackson's death was a homicide - but no further records have emerged about what was in the star's drug addled, stick thin frame. As yet police and California district attorney have not charged anyone.

Dad Joe wants the world and his family to see what substances were in his son's system and ask experts to unravel what triggered his son's fatal cardiac arrest on June 25.

The former manager of the Jackson 5 believes these documents will be the key in his planned private lawsuit case against Doctor Conrad Murray for wrongful death of his son.

He is still considering whether he will file an action against concert promoters AEG as to whether they were complicit in MJs treatment. Joe insists Murray was employed by AEG to " look after the star's needs."

Privacy

However estate administrators John Branca and John McClain reckon that most of his medical records should remain secret on "privacy" grounds forever.

In December LA judge Mitchell Beckloff denied Joe the right to contest Branca and McClain's right to govern the Thriller star's $1bn fortune. He is now hoping to bank a monthly allowance from his dead son's fortune.

A source close to the family said : "Joe is a father simply trying to learn the truth about his son's death ; the family have had to endure almost seven months with these records being kept secret .

"Now the estate, the people who are meant to be acting in Michael's best interests, are blocking him from doing that.

"Joe is asking for this information to establish how strong our case would be against Murray and any other

"The problem is Joe would need money from the estate to sue Murray on behalf of his son - but they don't want a part of it.

"Joe has to present his case for cash to the judge, but cannot do that without these records.

"We are going to fight this, but if we lose and the police either don't take the case to court or get a plea-bargain from Murray then Michael's health records will remain a secret forever.

"If the estate get their way just how Michael died will be hidden forever. His family and fans will not have peace with that. If there was foul play no-one will ever know why.

"It means the public may not know just what levels of drugs were in the star's body, what happened at Jacko's house and the hospital. These records are so important"

The source added: "This is a delaying tactic. If the case is made criminal all these documents will be released to the public. We cannot understand the administrators' stance."

Last night Brian Oxman, lawyer for Joe, told The News Of The World: "The world and Michael's fans should rise up in outrage that a grieving father should not be permitted to know how his son died."

The estate lawyers have filed a motion to block Joe's subpoenas to pull medical records from UCLA hospital and the coroners offices.

The row is set to explode in court when Joe, Branca and McCLain go head to head in the LA Superior Court on February 11.

So far coroners concluded Jackson died from an overdose of Propofol, a hospital based anesthetic drug which Dr Murray told cops he had injected.

Cops' affidavits also showed that Murray gave him a batch of prescription pills to help the star sleep hours after a rehearsal for his London comeback shows.

Court

However the autopsy, toxicology and hospital emergency room records have been kept under wraps.

Last night Howard Weitzman - legal representative for the estate's administrators - said: "Mr Jackson is not entitled to the records as set out in our court motion.

"He is before the court asking for a family allowance for his support and these records have no relation to that request.

"The motion and requested order protects Michael's privacy.

"If there is a criminal case against Dr. Murray the overwhelming number of items asked for by Mr Jackson will not be part of that case nor would they be released to the public."