Officers were called at around 11:30 pm (2130 GMT) on Friday to a street in the city’s 11th district, where the police source said a safe was found abandoned.

Inside a nearby hotel, they found the body of the night watchman “lying on his bed, tied up and with multiple bruises,” the source added.

A witness reported seeing four men wearing balaclavas trying to load the safe into a van at around 9:30 pm, before giving up and fleeing in the vehicle.

The safe “contained the hotel’s whole month of revenue,” the police source said.

The watchman had reported being assaulted around 10 days before by several people “claiming to be delivery men” who tried to steal the safe, the police source added.

The van used by the men to escape was found abandoned with its motor running at the busy Place de la Nation roundabout in southeast Paris.

Another witness reported seeing four people jump out of the van and take the metro.

Paris prosecutors told AFP they were probing suspected murder, theft and illegal confinement.

“An investigation is under way to find out the circumstances of this person’s death and the chain of events,” they said.