Abu Sayyaf extremists in the Philippines have released a video of the beheading of a German hostage.
The brief video circulated today by the SITE Intelligence Group, which monitors jihadi websites, is the first sign that the brutal militants proceeded with their threat to kill Jurgen Gustav Kantner in the southern Philippines after a Sunday ransom deadline lapsed.
The video shows Mr Kantner sitting in a grassy clearing and saying "Now he kill me", shortly before a masked militant beheads him.
A few gunmen are heard to mutter "Allahu Akbar", or "God is great".
Foreign Ministry spokesman Martin Schaefer said German experts were evaluating the video to determine whether it is authentic, but that if it is, it's "deeply shocking".
"It makes you question what can lead people to commit such a barbaric crime, but at the moment I'm not in a position to say whether the video's authentic."
The militants had demanded a ransom of 30 million pesos (around €575,000), officials said.
The Philippine military said in November that the Abu Sayyaf claimed its gunmen had kidnapped Mr Kantner and killed a woman sailing with him off neighbouring Malaysia's Sabah state.
Villagers reported finding a dead woman lying beside a shotgun on board a light blue yacht with the German flag and marked "Rockall" off Laparan Island in Sulu, the military said.
The predominantly Muslim province is where ransom-seeking militants have held many hostages in jungle encampments.
Mr Kantner was also kidnapped by Somali pirates years ago.