Police on Wednesday said they found evidence suggesting a German man who died two years ago may have been a serial killer who began killing prostitutes more than four decades ago.

The late suspect, identified only as Manfred S., died in August 2014 but police now suspect he may have been involved in the murders of five prostitutes and a teenager in and around the central city of Frankfurt.

Suspicions were raised when the remains of a female sex worker were uncovered in a bin in a garage he had rented, with police noting the “cruel method” used to murder the woman, who was addicted to drugs.

They said there was a “high likelihood that this crime was preceded by other homicides”.

Investigators were looking into the killings of four other prostitutes who, like the victim, came from Frankfurt. Two of the women were killed in 1971, one in 1991 and the other in 1993.

Manfred S., who was 67 when he died, was a landscape architect from the town of Schwalbach.

He is also a suspect in the 1998 murder of 13-year-old Tristan Bruebach, police said, pointing to similarities between the killings. Bruebach’s mutilated body was found in a tunnel on the outskirts of Frankfurt.