Theroux took to Twitter to call out fans who say the multiple allegations of abuse made against the singer are false, and referred to supporters as 'willfully blind'.
In a post today, he wrote: "If you can't see that Michael Jackson was a paedophile after watching @danreed1000 's film you are being wilfully blind. And if you are campaigning against it you are actively colluding in the silencing of victims."
Speaking to LADbible last month, Theroux said he was certain Jackson was a child molester.
He said: "I believe that Michael Jackson was a paedophile. He was never found guilty in a court of law, so someone would come back to me and say, 'Well, he's innocent until proven guilty' - to which I would say, 'Well, look, do some research and I think you'll find that the evidence is compelling.'"
Some fans refuse to believe the disturbing claims of serial child abuse, however.
Wade Robson (left) and James Safechuck (right) both claim to have been abused by the singer. Credit: PA
Replying to Theroux online, one person said: "This is the first time I've ever disagreed with you Louis. Why wait until now, after every other avenue to fame and fortune has already expired? Why remain so close to the Jackson name and family all these years and suddenly remember everything when a cheque was dangled?"
Another added: "It's people trying to make money out of somone else's wealth."
A third person wrote: "Oh Louis, I love watching your documentaries but as far as I am concerned these fame hungry, money mad fools need to drop this BS. I am sickened and outraged that any channel would even broadcast this farce and as for the mothers, don't get me started."
The debate was sparked following the first part of hard-hitting documentary Leaving Neverland, which aired in the UK on Wednesday night.
The film followed the story of Wade Robson and James Safechuck, who both claim to have been sexually abused by the late singer as children.
Recounting the alleged abuse, Mr Safechuck claimed that his penis swelled up after masturbating with Jackson and that the singer - who died in 2009 aged 50 - made him bend over and spread his backside.
Many viewers described how they felt 'physically sick' listening to the detailed descriptions of the alleged abuse some of the men were subjected to.
One person said: "I was so excited to watch #LeavingNeverland but now I'm not sure why. I feel physically sick watching these two brave men give such a graphic description of the abuse they experienced from someone the world idolised."
Another said: "Feel physically sick watching this and hearing this. Knowing I have a little boy and knowing these boys went through this is sickening."
The second part of Leaving Neverland will air on Channel 4 tonight at 9pm.
Featured Image Credit: PA