KASSEL – A self-declared cannibal goes on trial in Germany on Wednesday to answer a murder charge in a case which legal experts say is without precedent in the country.

The gruesome details of how Armin Meiwes cut up and ate parts of his victim before a running video camera have received widespread coverage since the 42-year-old computer expert and former soldier was arrested last December.

Now more than 30 witnesses and several specialists will be giving evidence in a case which has attracted huge media interest from around the world and has taken investigators into new territory.

With Meiwes already admitting to killing his victim – a 42-year- old engineer from Berlin he had met via a contact ad on the internet – the trial will hinge on a key question: did the victim freely consent to be killed?

With cannibalism itself not illegal under German law, Meiwes is charged with murder “for sexual satisfaction” in March 2001 as well as “disturbing the peace of the dead” for butchering the corpse. He could be jailed for life.

But his defence lawyer will argue that the victim, named only as Bernd-Juergen B., had asked to be killed, which warrants the lesser charge of “killing on demand” and carries a maximum five-year jail sentence.

The facts of the case are horrific enough. When police acting on a tip-off searched Meiwes’ large half-timbered house at a village near Rotenburg south of Kassel they were shocked to find bags of human flesh packed away in a freezer.

Videos were also seized which showed how Meiwes cut off his victim’s penis which both men then attempted to eat. Later Meiwes stabbed his unconscious victim to death with a kitchen knife, cut him up and gradually prepared parts of the body to be eaten.

The unused parts of the body were buried in the garden.

Investigators have examined 12,000 e-mails, more than 1,600 picture data, more than 220 computer hard disks and several CD-ROMS and diskettes directly related to the killing. Meiwes was reportedly in contact by e-mail with 430 people interested in the subject of cannibalism.

Harald Ermel, the lawyer acting for Meiwes, said the videos will show that the victim had volunteered to be killed and eaten.

Ermel is also expected to call as witnesses four other men – a teacher, a cook, a student and a hotel employee – who had also lived out their cannibalism fantasies with Meiwes.

All had been hung on a butcher’s hook in a “slaughter room” at the house but none of them were killed because their death wishes were not explicit enough, the court is expected to be told.

Meiwes himself is no monster, Ermel insists. Although “somewhere abnormal” he is “courteous, affable and helpful”, he said in a recent newspaper interview.

Neighbours and former colleagues have also described Meiwes, who has no previous convictions, as friendly, modest and polite, always willing for a chat over the garden fence, to share a cup of coffee or to take part in village activities.

In a recent interview from jail, Meiwes said he regretted his actions and no longer had the urge to eat human flesh. He intends to write his memoirs to deter others, he said.

Legal experts believe prosecutors may have a tough time proving their case. Reinhard Merkel, professor at the Hamburg University Institute for Criminal Science, said there appeared to be “a causal link” between the killing and the victim’s desire to be killed.

In such a case whether the initiative came from the victim or not was not relevant. What was important was whether or not the victim acted voluntarily and had control over proceedings until the end.

Meiwes is unlikely to be referred to a psychiatric unit in view of a specialist report which showed he was fully aware of the crime, according to media reports.

Whether he is jailed for life or given a much milder sentence now depends on how the criminal division of Kassel district court interprets the evidence it hears in a trial scheduled to take 14 days. Sentencing is expected in January.