Rihanna's security block Justin Bieber

He was the star of the show at this year’s Billboard Awards, but Justin Bieber found himself on the wrong side of Rihanna's security detail when he attempted to approach her backstage.

Despite scooping six gongs at the event – which he attended with girlfriend Selena Gomez – the 17-year old singer was ‘mortified’ after trying to grab the R&B star's attention, only for his efforts to be thwarted by members of her security team.

“Justin thinks Rihanna is the most beautiful woman and supremely talented,” a source told British paper the Daily Mirror. “He is in awe of her. Justin is a red-blooded teenager, he can’t help acting like a love-sick puppy-dog when he’s around her.“The pair were chatting as Justin’s girlfriend Selena looked on, scowling. Then Rihanna got dragged away by a couple of her friends. The pair resumed their chat later but when Justin went to talk to her at the show’s climax her security blocked his path, telling him to ‘leave it.’”

The source added: “Justin looked mortified. He thought they were buddies.”

The singer has since flown out to Hawaii for a sunshine break with Disney star Selena – with whom he made a first public appearance at the Vanity Fair Oscar viewing party in February.

The pair were spotted holding hands after jetting into Maui from LAX airport in Los Angeles on Monday.