UFC heavyweight champion Brock Lesnar is returning to the octagon ? #UFC

The buzz on social media this past week has been that former UFC heavyweight champion Brock Lesnar is returning to the octagon.

But if he is, UFC president Dana White isn't giving anything up.

"Really?" White said quizzically when asked whether Lesnar was attending Saturday's UFC 168 in Las Vegas. "I don't know. I honestly don't know."

Honestly?

"Honestly," White told MMAjunkie. "I don't know."

What White does know is that a Lesnar (5-3 MMA, 4-3 UFC) return would be huge for the UFC's business. The hulking heavyweight did big numbers each time he fought on pay-per-view, reportedly cracking 1 million buys on four occasions.

But regardless of whether or not White has something up his sleeve, his response is likely to generate a fresh round of speculation on Lesnar's return, which has persisted despite his retirement in late 2011.

In late 2012, White said Lesnar contemplated fighting again, but was "never coming back."

Lesnar debuted in the octagon at UFC 81 and beat Randy Couture to take the belt at UFC 91. His title reign lasted nearly two years before Cain Velasquez defeated him at UFC 121.

During his UFC career, Lesnar suffered multiple bouts of diverticulitis, an intestinal disorder, and underwent surgery after a second bout. He retired following a first-round TKO loss to Alistair Overeem at UFC 140.

Lesnar subsequently signed a contract with pro-wrestling leader WWE, where he first gained stardom. He most recently appeared in the wrestling ring for the promotion's "Summer Slam" series