Canadian pop star Justin Bieber did it again - that is misbehave onstage. However, his latest caper was triggered by a hard-headed fan who threw at iPhone onstage in spite of Justin's request to refrain from throwing items to the stage.

"Do you guys want me to keep performing or what ... Refrain means don't throw things on stage," Huffington Post quoted the 19-year-old singer.

However, one fan insisted in throwing an expensive iPhone despite Bieber's request. To get even, he got the Apple-branded gadget, placed it inside his low-rise pants and rubs it against his privates. Then Justin gave the crotch-smelling iPhone to another fan.

The mischievous act was met by decibels of shrieking, Huffington Post reported. The YouTube video has become viral with more than 537,000 views.

"I said don't throw stuff on stage and this is what they, they throw a phone on stage. I mean, I do need a new iPhone," he said.

Bieber had previously been heavily criticised for his bratty ways, including allegedly spitting at a neighbour and fans, pissing on a mop bucket and speaking against a former U.S. president.

There is no indication if the original owner of the iPhone thrown onstage attempted to get back the device from the other fan.

The incident happened Tuesday night at Bieber's concert at the Prudential Center in Newark, New Jersey.