The phone started burning at the bottom just by the charging port.The pics show where it has been burnt, with scorch marks and melted plastic around the charging slot.
He said 'I was driving along with my Galaxy S3 in my car mount when suddenly a white flame, sparks and a bang came out of the phone I pulled in to look at my phone, the phone burned from the inside out. Burned through the plastic and melted my case to my phone. The phone kept working but without any signal.
'The phone was destroyed and it slightly burned a piece of plastic on the inside of my car.'
He added: 'I'm really annoyed. That could have burned the side of my face or through my pocket and my leg, or set fire to my bed. It's very dangerous.'
The Galaxy S3 has sold more than 10 million worldwide and was one of the fastest-selling gadgets of all time after its launch in May this year.
Samsung said it will examine the claim, to check if the phone is susceptible to overheating. The company is now trying to get hold of the unit for a proper examination.
A spokesman said: 'Samsung is aware of this issue and will begin investigating as soon as we receive the specific product in question.
'Once the investigation is complete, we will be able to provide further details on the situation.'