Suspected serial killer Manfred Seel, who is believed to have murdered 10 people including a 13-year-old boy may have eaten some of their body parts

A suspected serial killer who is believed to have murdered 10 people including a 13-year-old boy may have eaten some of their body parts, according to police.

Detectives investigating the case of Manfred Seel dubbed the German Jack the Ripper, confirmed that a possible motive for the killings by the now dead 67-year-old may have been cannibalism.

Seel, from Schwalbach near Frankfurt, appeared to be an ordinary family man who worked as a gardener and general odd job man. In his spare time he played saxophone, but died in August 2014.

When clearing up a garage that he had rented, his daughter came upon the remains of a dismembered corpse, sparking an investigation that quickly widened to include five other victims, and then an additional four.

One of the victims was Tristan Bruebach who disappeared when he was walking home from school in 1988 and his mutilated body was found in a tunnel near Frankfurt.

Now police say that when the 13-year-old boy was discovered, his testicles had been removed and they have never been found.

They also found that parts of his backside and pieces of the leg as well as other muscle parts had been sliced away.

Officers said the child's body had been disfigured in a way similar to Seel’s other victims.

Their wounds also matched those depicted in violent pornography found on Seel's computer. He had more than 3,200 violent images, some depicting cannibalism.

Frank Herrmann of the State Criminal Investigation Office (LKA) who is one of those investigating the case said that the suspected killer had led an apparently law-abiding life.

And he confirmed that the investigation into the suspected killer, which has been given the codename task force Alaska, was also looking at the possibility of the bodies being at least partly eaten too.

Mr Herrmann said: 'I can confirm that at least in the case of Tristan it is a distinct possibility and we are investigating it.'

With regards to the missing teenager's testicles he said: 'In many cultures the testicles are regarded as an aphrodisiac and they are supposed to increase sexual desire.

'On online platforms devoted to cannibalism they are absolutely the most often discussed food item.'

Some of Seel's suspected victims. Among them is 13-year-old Tristan Bruebach, whose body was found with some organs missing

Police are almost certain that the woman whose body was found, the prostitute Britta D., was murdered by Seel. They said that she had been dead around 10 years when the body was found.

The other dead include four sex workers who disappeared near Frankfurt's central rail station in the 1970s and 1990s.

Gudrun Ebel and Hatice Eruelkeroglu were both murdered in 1971, Gisela Singh in 1991 and Dominique Monrose in 1993.

Police said that the women's bodies had been badly mutilated, with their arms and legs cut and internal organs removed, further underlining the possibility of cannibalism.