Sydney cyclist has skin graft surgery after phone explodes

A Sydney cyclist had to undergo skin graft surgery after a "one in one million" accident led to his phone exploding in his pocket.

Bondi resident Gareth Clear, 36, was riding around the Manly Da mountain bike track on Sunday afternoon when he fell off his bike and landed on his iPhone 6, The Daily Telegraph reports.

Just seconds later he felt intense heat burning his leg and saw smoke coming from the device before it exploded.

The blast melted through his shorts and two layers of his skin on his upper right thigh.

Mr Clear later underwent skin graft surgery in the burns unit of the Royal North Shore Hospital with his recovery expected to take weeks.

He emphasised the phone he bought only six months earlier did not spontaneously combust.

"It was a one in one million chance I hit a part of the phone which pierced the lithium battery and it exploded," Mr Clear said.

However, Dr Da-Wei Wang from the UNSW faculty of chemical engineering said that mobile phones batteries overheating and exploding were not uncommon.

"I think many examples show that, if you search on Google there are many images of mobile phones which have been overcharged, which may cause it to be overheated," he said.

Dr Wang said an explosion caused by an impact could be the result of overheating as well as a structural flaw.

Mr Clear said he has alerted iPhone manufacturer Apple to the incident and they are investigating.