The singer was one of the 11 remaining hopefuls on the singing competition show filmed in Sydney.
According to Sky News, the Seven Network has released a statement saying that Brookes has been sent home due to behaving "in an inappropriate manner."
The statement reads: "During an out-of-hours social media session, Josh behaved in an inappropriate manner that put him in breach of his responsibilities to the programme.
"After a careful review of the incident, FremantleMedia Australia, producers of the programme, together with Channel Seven, made a joint decision to remove him from the competition."
The Perth native apparently had an unauthorised Twitcam session with recently-eliminated contestant Adil Memon on Tuesday (September 18).
During the session, Brookes allegedly attempted to get nude photos from several of his 24,000 followers.
Brookes, 20, will now return home to Perth, while Memon has reportedly deactivated his Twitter account.
Seven Network reports that they plan to find a replacement for Brookes, who was mentored by judge Mel B, in the coming week.