Police are treating the sudden death of a man at a home in Lethbridge on Monday morning as suspicious and say there is no ongoing risk to the public.

Emergency crews were called to a duplex in the 1200 block of 9 Avenue North at about 7:20 a.m. for reports of an injured male.

The man was pronounced dead at the scene and has been identified as a 45-year-old Lethbridge resident.

Lore Buchmann lives across the street and says it is a quiet neighbourhood.

"Never had any problems, until, this is the first really bad time and I'm sad to see that I hear that it could be bad," she said.

Other residents in the area say this isn't the first time that police have attended the home.

A man who lives in the other half of the duplex says he called 911 after a woman rang his doorbell asking for help.

The man says he went into the home and did CPR on the victim until paramedics arrived.

The victim's name has not been released and an autopsy on the body has been scheduled for later in the week.

Police say the investigation is in the early stages and that there is no risk to the public.