Passersby in the Eaux-Vives neighbourhood were shocked to see the dead man’s arm dangling from an opening in the bin on Sunday.
The victim, a foreigner born in 1990, died from asphyxiation from a “compression of the neck”, the Tribune de Genève newspaper reported, citing information it obtained from an autopsy.
Forensic scientists found no other signs of traumatic injury, the newspaper said.
Prosecutor Dario Nikolic believes the death was probably accidental, although the investigation is continuing and the possibility of a criminal act has not been completely ruled out.
It remains unclear what the man was doing in the clothes box, whether he was trying to retrieve clothes or seek a warm place to sleep during what was reported to be a cold night.
Nikolic has ordered toxicology analysis to determine whether the man was under the influence of alcohol or drugs, but the results from this will not be known for several months, the Tribune de Genève said.
Investigators have also taken DNA samples for analysis and are continuing to question residents in the neighbourhood.