On September 4th, 2012, less than three weeks before UFC 152, an email with Belfort's lab results was accidentally sent out to a slew of fighters and managers that contained questionable test results. It did not stop the UFC from allowing him to face then-champion Jon Jones in the main event of UFCM 152.
Josh Gross detailed the entire story for Deadspin, while BloodyElbow's John Nash provided a follow-up. It became clear that Belfort was allowed to abuse the therapeutic use exemptions for testosterone. He then went on to face an unaware Jones, whose manager later took to twitter to express his anger for him.
Askren: 'I'd be so annoyed if I was' Jon Jones
Ben Askren's take on Jon Jones not being alerted to Vitor Belfort's pre-UFC 152 drug test results? He'd be annoyed.
The UFC is yet to provide an official statement following the recent revelations.