A German computer technician accused of killing and eating the flesh of a man, who agreed to the deal over the Internet, has gone on trial for murder, report agencies.

Armin Meiwes, whose trial started December 3,  is charged with murder as no crime of cannibalism exists in Germany.

The case is the first of its kind in the country. Dressed in a dark suit, Meiwes, from Rotenburg-an-der-fuld in central Germany, appeared relaxed as he sat down next to his lawyer at the Kassel state court, said CNN.

In interviews to the media, the 42-year-old defendant has expressed regret for his actions.

Meiwes reportedly cut off part of the victim's body before the pair ate it together. He then killed and cut up the victim, storing his body in a freezer and eating it over the following months.

The defence is expected to argue that the victim, a 43-year-old computer technician identified only as Bernd Juergen B, from Berlin, agreed to the macabre event, says CNN.

The defence is believed to be seeking a charge of killing on demand, which carries a maximum five-year sentence if proven, rather than murder which holds a possible life sentence.