The mummified body of a German adventurer has been discovered inside an abandoned yacht.

The grisly discovery came after two fishermen off the coast of the Philippines alerted authorities to a drifting vessel.

The body, found slumped near the boat’s radio telephone, has been identified as 59-year-old Manfred Fritz Bajorat.

Inspector Mark Navales said the cause of death was unclear, but there were no signs of foul play.

“It is still a mystery to us,” said Navales, adding it looked like Bajorat “was sleeping.”

It was unclear how long Bajorat had been missing, but there had been no reported sightings of him since 2009.

Forensic examiners concluded that Bajorat died more than four days before the yacht was found on Thursday by fishermen in the Philippine Sea about 60 miles from Barabo.

Items inside the yacht were scattered, according to Navales, who said the man’s wallet was not found but that the yacht’s radio, GPS and other valuable items were still there.

Local police spokeswoman Goldie Lou Siega in the Philippines said: “We have no evidence of a second person aboard and no weapon was found on the yacht.”

Dr. Mark Benecke, a forensic criminologist in the German city of Cologne, told BILD newspaper: “The way he is sitting seems to indicate that death was unexpected, perhaps from a heart attack.”

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