Police were called to the home on Rock City Road by the man early Wednesday night.
Const. Gary O’Brien said members of the Nanaimo RCMP Serious Crime Unit and Forensics Unit are carrying out a search of the apartment.
“There has also been no confirmation made on what relationship, if any, existed between the deceased and the accused,” he said.
The BC Coroner’s Service has been advised and the apartment is expected to remain under police control for most of the day.
The deceased has not been named and no formal charges have been laid.