A man's suspicious death in a south Minneapolis apartment on Tuesday is now under investigation by the Police Department's homicide unit, according to police. No arrests have been made, but authorities are interviewing witnesses and "several people of interest."

A 5 p.m. 911 call reported a man not breathing, according to a news release issued Wednesday. When officers arrived at the apartment in the 1200 block of Eighth Street South, they found the body of an adult man. He has not yet been identified.

Also on Wednesday, the Police Department said it could use help tracking down the last known whereabouts of Michael Duane Portlance, 58. Portlance, who was also known as "Sonny," was found dead lying near a fence in the 2600 block of Nicollet Avenue South on the morning of Oct. 4. His death was ruled a homicide.

Anyone who knows where Portlance was in the days and hours before he was found dead, or who knows his acquaintances or recent roommates should call Minneapolis police Sgt. Christopher Thomsen at 612-673-3577.

The city has seen 31 homicides so far this year, according to police statistics.

Matt McKinney • 612-217-1747