Bieber, who often walks to the ring with Mayweather before fights, had to convince the bodyguard he was who he said he was - because the guy didn't recognise the Baby singer with his new platinum hair.

In a video clip of the encounter, obtained by TMZ.com, Bieber was prevented from walking to the ring after his friend won his 49th fight by unanimous decision.

The security man can be heard asking the pop star, "You wanna be escorted out in handcuffs, young man?"

Bieber played it cool and eventually got to the fight winner to congratulate him.