The death of a man in Nowra on Monday is no longer being treated as suspicious.

Police said a post-mortem on the 51-year-old has been completed and results have revealed there are no suspicious circumstances surrounding his death.

A report will be prepared for the coroner.

Emergency services were called to a Douglas Street unit on Monday morning after concerns were raised for an occupant, with the man's body found inside one of the units.

Police carried out a thorough investigation into his death, with teams of forensic officers scouring the unit for evidence for almost two days, including removing a number of items from the property.

Police remain tight-lipped about the circumstances surrounding the man's death.

Update: 10.20am

Homicide officers are assisting Nowra detectives with investigations into the death of a 51-year-old man in Nowra on Monday.

Police remain tight-lipped about the circumstances surrounding the man's death in a Douglas Street unit, just streets from the centre of the Nowra CBD, saying that it was "suspicious" and that investigations "were ongoing".

A post-mortem will be conducted on the man in Sydney today, with detectives hoping it could shed some light on the cause of death.

Police remain at a six-unit complex, with officers continuing to stand guard over the location, which is yet to be released by investigating detectives.

Emergency services were called to a unit on Monday after concerns were raised for an occupant.

Upon arrival, the body of the man was found inside one of the units.

Police have spent almost two days at the property, with teams of forensic officers combing the scene in an attempt to gain evidence or any clues into what might have happened.

Processing the crime scene has been a lengthy procedure, photographing and categorising every detail, and although it was understood there wasn't much in the unit, police say it has to be thoroughly processed.

It is understood the unit is a single bedroom with an attached laundry area.

Police would not confirm the name of the dead man, despite it being reported in other media outlets, saying they would not release a name until it was confirmed all next of kin had been informed.

Once investigations are concluded a report will be prepared for the coroner.

Tuesday, June 11 2.15pm:

South Coast Police are treating the death of a 51-year-old Nowra man as suspicious.

Police continue to investigating the circumstances surrounding the man's death in the Douglas Street unit.

Emergency services were called to a unit just before midday, on Monday, June 10, after concerns were raised for an occupant.

Upon arrival, the body of the man was found inside one of the six-unit complex.

Officers from South Coast Police District established a crime scene and began inquiries into the circumstances surrounding the death.

Forensic officers have been at the unit for more than 24 hours, continuing to gather evidence, while there is a large police presence at the location.

A post mortem examination will be carried out to determine the cause of the man's death; however, investigating officers are treating it as suspicious.

Inquiries are continuing, and a report will be prepared for the information of the Coroner.

Anyone with information about this incident is urged to contact Nowra Police on 4421 9699 or Crime Stoppers: 1800 333 000 or https://nsw.crimestoppers.com.au.

Earlier:

Police are investigating the death of a man in a unit, just streets from the Nowra CBD, on Monday.

Police were called to the Douglas Street unit late Monday morning where they found a 51-year-old Nowra man dead.

The dwelling is part of a six-unit complex.

A crime scene was established and forensic officers examined the scene.

Nowra detectives are continuing investigations into the possible cause of the man's death.

Late Monday afternoon Shoalhaven City Council rangers were also called to the property to remove a dog that was inside.

The crime scene remains in place with the South Coast Police District's mobile command centre being at the location overnight.

Police say investigations into the man's death are ongoing.

Once investigations are concluded a report will be prepared for the coroner.

Read more: Court/Crime