A Dublin-based consumer posted comments and photos on a web site on Wednesday saying his Galaxy phone exploded while mounted on his car dashboard.
"There's no confirmation it was a fault with the phone. It may actually have been caused by a combination of my car mount and my car's heating system," the consumer wrote.
There have been other reports of Samsung smartphones overheating or exploding. In March, a Korean schoolboy reported that a spare battery for his Galaxy S II exploded in his back pocket. Samsung said then that massive external pressure or force caused the explosion.
"Samsung is aware of this issue (in Ireland)," the company said on its official blog. "Once the investigation is complete, we will be able to provide further details. We are committed to providing our customers with the safest products possible and are looking at this seriously."
A spokeswoman said on Friday the company was still looking into the matter.
Heat issues have been reported with other devices. In March, influential consumer watchdog Consumer Reports said Apple's latest iPad tablet threw off a lot more heat than the previous version, lending weight to complaints on Internet forums that the device could get uncomfortably warm after heavy use.