The head of a German serial killer known as the "Butcher of Hannover" has been cremated after lying in storage for 89 years.

The Goettinger Tageblatt newspaper reported that the University of Goettingen's medical department confirmed it had incinerated the remains of Fritz Haarmann last year. Haarmann was beheaded with a guillotine in 1925 after being found guilty of murdering more than two dozen young men between 1918 and 1924. The case is said to have served as one of the inspirations for Fritz Lang's 1931 thriller "M." After his death, Haarmann's head was preserved in formalin and kept for research purposes