A private doctor who went on tour with pop legend Michael Jackson and introduced him to the drug that went on to kill him has defended the star's bizarre behaviour by calling it a "celebrity thing".

Neil Ratner, who dubbed himself the 'Rock Doc' after his switch from a career in music to medicine, has said the way Jackson acted was "a celebrity thing" and nothing more, reports thesun.co.uk.

Ratner toured with Jackson for eight years as his private physician in the 1990s and has spoken out about the sexual abuse allegations against him almost 10 years after the singer's death.

He said he was the "Beat it" hitmaker's confidant and that the singer would often speak of his own childhood traumas and was obsessed with "childhood innocence".

"The oddest part of Michael (was) his inability to grow up. His inability of wanting to be an adult. That was his hangup. Did he like children more than adults? Probably," Ratner told the publication.

He believes that Jackson's own lack of childhood led to psychological problems.

The now-retired anaesthesiologist was a regular guest at the Neverland ranch, but says he didn't witness any abuse.

It comes after the controversial documentary film "Leaving Neverland" , where James Safechuck and Wade Robson alleged they were both sexually abused by Jackson when staying at the sprawling property.

In the film, Robson and Safechuck alleged that Jackson had abused them from the ages of 10 and seven respectively after they were befriended by the King of Pop.

The Jackson family hit back at the allegations.

Ratner, who claims to have spent a lot of time in Michael's bedroom, believes he would have seen the abuse if it had occurred. But he doesn't discount that something could have happened.

The superstar, who was previously tried on child molestation charges and acquitted on every count, died in 2009 at the age of 50.

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