German authorities have arrested a police officer who allegedly killed and chopped up a man he met on an internet website for people obsessed with cannibalism.

The 55-year-old officer, a handwriting and document analysis specialist identified only as Detlev G, was arrested at his workplace in the eastern city of Dresden.

Police said that Detlev admitted fatally stabbing his victim, a 59-year-old man from Hanover whose name has not been released.

Police said that the two met on a chatroom for people interested in torture sex. The killing took place hours after the two men met in person for the first time, police said.

Dresden city police chief Dieter Kroll said that Detlev confessed to chopping up his victim into numerous piece and burying the parts in various spots around the property near the town of Hartmannsdorf-Reichenau, south of Dresden.

The victim had long fascinated by cannibalism, said a colleague.

"The missing man had fantasised since his youth about being killed and eaten by another person," Kroll said.

Prosecutor Lorenz Haase said there was no immediate indication that Detlev had eaten parts of his victim's body.

"He said that his victim wanted to be killed and he fulfilled this wish," Haase said.

"[The case] will show how easily people can come together with the most gruesome fantasies on the internet and exchange their perversions in increasingly crass manner," Kroll said.

"In 99% of cases, they get their kick out of the exchange."