"Brock Lesnar is still under contract with the UFC. He is not going to wrestle in the WWE. He cannot wrestle, box or fight anywhere else."
Speaking via TMZ.com, UFC President Dana White tried to end rumors about Brock Lesnar's departure back to the WWE. Lesnar was involved in a face-to-face confrontation with the Undertake after his defeat against Cain Velasquez at UFC 121, sparking rumors about the WWE offering him a contract to fight at Wrestlemania 27.
UFC have a well-known policy about fighters going to other organizations, and it looks like Dana White is not going to make any exception for the former Heavyweight Champ. Wrestling Observer's Dave Meltzer has some interesting thoughts about the situation: