Police in the western German city of Bonn said on Wednesday they had halted a homicide investigation against a 38-year-old man suspected of placing a severed head outside a city court and the rest of the body in the Rhine River. 

Police first found the severed head outside the court on Tuesday and said they believed a headless torso in the river would prove a match for it. 

An autopsy later revealed that the two parts did make one whole, but also that the deceased man was already dead when his head was cut off.

"After the criminal autopsy carried out on the 44-year-old's corpse on Wednesday morning, it is clear that the separation of the head from the torso was not the cause of death," Bonn police said in a statement.

"According to the results of the investigation, the victim had already died of natural causes as a result of a serious illness by that time." 

Investigations continue, arrested suspect has not acknowledged involvement

Police however said that they had still issued an arrest warrant against a 38-year-old suspect apprehended on Tuesday. 

Prosecutors are now investigating the man on suspicion of having desecrated or tampered with the dead. 

Police also noted that the 38-year-old, who was arrested "in the immediate proximity" of where the head had been dumped, had not admitted guilt or involvement in the case.

Eyewitnesses had first called to notify police of the head's presence around 5:35 p.m. local time on Tuesday, and police said its first units on the scene had identified and detained the suspect on arrival. 

According to police, both the victim and suspect are thought to be members of Bonn's "homeless scene."

msh/rs (AFP, dpa)