A Samsung S III smartphone said to have overheated after a malfunction probably sustained the damage after being deliberately put inside a microwave oven, an independent investigation has concluded.

Several weeks ago a Samsung forum poster in the Irish Republic gained attention to an apparently serious fault, said to have occurred while the smartphone was sitting in an in-car dock.

An image showed the affected handset with melting damage on one end that could have been caused by an overheating battery or circuity.

"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 user reportedly wrote.

Conscious that the S III is the company's appointed iPhone killer, Samsung immediately had the handset looked at by third party organisation Fire Investigations UK (FIUK), the official draft of which has now reported that the damage had to have been caused by an external course, most likely a microwave.

"The only way it was possible to produce damage similar to the damage recorded within the owner's damaged device was to place the devices or component parts within a domestic microwave," the report said.

The owner of the phone has since retracted the claim of the in-car fire, posting that the phone had in fact been damaged after a misguided attempt to "recover the phone from water."

By releasing the report, Samsung will feel vindicated.

"The owner should be questioned as to why the moisture detection patch had been removed from this device and any other curcumstances surround [sic] the damage caused to the owner's device.," the FIUK report concluded.

Overheating smartphones and tablets are part and parcel of the publicity obstacle course makers have to contend with, overheating being a common theme.

In March, Apple had to field some concern over allegedly overheating iPads on its user forum. Sometimes the fears are well-founded. In January, HP agreed to pay $425,000 (£274,000) to settle claims over overheating laptop batteries from 2007.