A commando-trained sailor who went on the run after slashing his six-year-old son’s throat has been found dead in a reservoir in Poland.

Survival expert Grzegorz Borys, 44, had been missing for 17 days after the body of his son Olek was discovered at the family home in Gdynia by his horrified mother.

Borys had last been seen on CCTV security camera footage dressed head to toe in black and carrying a backpack disappearing into a forest.

The combat-trained able seaman’s body was found on 6th November under a floating pontoon at the Tricity Landscape Park just a ten-minute walk from the family home.

Police found two gunshot wounds to his head and cuts that officers believe could have been suicide attempts.

But an autopsy, reports local media, revealed that he actually died from drowning.

Borys’s disappearance sparked one of the biggest Rambo-style manhunts in Polish criminal history with more than 1,000 officers, helicopters and tracker dogs mobilised.

One neighbour told local media: “He was such a commando who could stay in that forest for a week without coming out.

“He might have had some hiding place there. It’s difficult terrain, there are holes, ravines. The chances of finding him are minimal.

“He knows the forest very well, and on top of that, he trained hard, could run even 40 km at once. Maybe he had prepared something there in advance?”

Another terrified local said: “If he killed his own son, he can kill anyone.”

A spokesperson for the Gdansk District Prosecutor’s Office, Grazyna Wawryniuk, said of the body: “I can confirm that it belonged to Grzegorz Borys.”

Pomeranian police spokesperson Karina Kaminska said: “The man was found beneath one of the floating islands that officers cut open to thoroughly search the areas.”

Forensic experts believe his body had been in the water for nearly two weeks before it was discovered, reports local media.