A heartbroken husband told firefighters that he tried to save his wife after the boat they were sleeping in caught fire in the middle of the night while moored on a river in Italy.

The German tourist was seriously burnt and only survived by jumping into the river after thick black smoke stopped him from reaching her.

Investigators believe that a short circuit or a fault in the gas system may have caused the blaze on the Stella River in Palazzolo, in the north-eastern Italian province of Udine, on Wednesday, 23rd April.

Distressing video footage shows the fire ripping through the vessel as firefighters battle to put out the blaze.

The woman, who has not been named, was asleep with her husband when the blaze broke out.

He told rescuers that he woke up after hearing some suspicious noises and went up onto the deck to investigate.

He said that he then tried to return below but was thwarted by thick smoke billowing from the cabin.

He said that he tried to reach his wife but was overwhelmed by the flames and threw himself into the water after suffering serious burns.

He was rushed to hospital by helicopter after the alarm was raised at around 3 am.

Firefighters managed to put out the blaze and prevented it from spreading to other vessels.

The boat then sank and divers later found the lifeless body of the woman in the remains of the vessel.

The tragic incident is being investigated by the Italian authorities.

(Joseph Golder/newsX)