North Wales Fire and Rescue say a body was found at a terraced house in Ffordd Llanllyfni, Penygroes, when they arrived to tackle a blaze on Tuesday afternoon.
The body was discovered in the kitchen at around 3pm by fire crews from Caernarfon. More details are expected later.
More top news
Well a fabulous day today has ended on a spectacularly soggy note for some! Heavy rain, hail and thunder will work northwards overnight!
The Talyllyn runs from Tywyn, near Aberdovey, for more than seven miles to two villages in the south Gwynedd countryside.
Homes in parts of Tonypandy and Llwynypia are without water this evening due to a burst water main at Cilfynydd.