“We think it's clear in this case that malevolence and brutality, both requisites for a murder charge, exist,” said state prosecutor Axel Bieler on Thursday.

Ambulance crews took the severely burned woman to hospital on Wednesday morning after pedestrians found her on a street on the outskirts of Kiel. She was taken to a specialist clinic shortly afterwards, but later died from her injuries.

The man and woman, both originally from Togo, had lived in Germany for around 20 years with permit residency status, police report.

Authorities added that they believe the motive for the crime was a relationship dispute between the husband and wife, who lived separately from one another.

The Kieler Nachrichten reports that he man poured fuel over his wife before setting her alight. Police sources told the newspaper that a “fire accelerant” had been used.

The paper also spoke to witnesses who said that the woman ran down the street away from the suspect as flames rose from her body. Several people attempted to put out the fire, but struggled to do so.

The suspect's trousers also reportedly caught alight. But he was able to put out the flames before fleeing into a nearby industrial area.

Police say they are questioning several witnesses in order to establish the course of events.