A former German police officer jailed for murdering a willing victim he met on a website for cannibalism fetishists is to appear in court again today (1 November) after his conviction was overturned on appeal.

Detlev Günzel, 58, was last year sentenced to eight years and six months in jail by a court in Dresden after being convicted of the murder of Wojciech Stempniewicz in 2013.

The court found that Günzel killed Stempniewicz in a specially designed S&M chamber he built in his cellar, then buried his body parts in his garden. Prosecutors found no evidence that Günzel had cannibalised his victim, AFP reported.

However, the verdict was overturned when Günzel's legal team successfully argued that the defendant's claim that the victim died after strangling himself had not been sufficiently investigated.

The Federal Court also found that the regional court had failed to impose a sufficiently lengthy prison sentence. Günzel was given less than the minimum 15 years for murder after the court found his victim had wanted to die.

Günzel, who had worked in the German police force for three decades, met Stempniewicz in October 2013 on a website for cannibalism fetishists billed as the "#1 site for exotic meat" which had 3,000 registered members.

His defence team argued that Stempniewicz had hanged himself in the defendant's S&M studio in his Hartmannsdorf-Reichenau home before Günzel dismembered the body.

Günzel initially told police he had murdered Stempniewicz by cutting his throat, but subsequently retracted the confession.

Investigators had testified in the first trial that they could not definitively determine the cause of death due to the state of the corpse.

Günzel and Stempniewicz had made contact by email and telephone before arranging the fatal date on 4 November, 2013.

A 50-minute video Günzel made was played during the trial, which showed him wearing only his underwear while dismembering the body as pop music played in the background.

He spent a total of four hours cutting up the body with a knife and saw before burying it in the garden.

Parallels were drawn with German cannibal Armin Meiwes, who admitted killing, mutilating and eating the flesh of a lover in 2001 after meeting him on the internet via an advertisement looking for a "slaughter victim". He was sentenced to life imprisonment in 2006.