On Monday night, 300 residents had to flee their apartment complex in Gladstone Avenue after a fire started in a fourth-floor unit.

The resident of the unit, an elderly woman, was the only casualty of the blaze and was taken to hospital suffering smoke inhalation.

The fire badly damaged the unit and threatened numerous other apartments within the nine-storey complex.

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Residents left the building and headed to the designated evacuation point, inadvertently hampering the efforts of firefighters who were trying to get into the building.

On Thursday, the strata management body placed a notice at the complex suggesting people may have been infected while at the evacuation point.

The notice advised of at least one positive COVID case within the apartment - the notice is unclear on how many cases there are.

"We are informed the positive cases did attend the evacuation point on Monday night, therefore it is highly likely you may be considered a casual contact," the notice from Illawarra Strata Management stated.

"We suggest you get tested for COVID-19 and self-isolate until you receive a negative result."

A photo of residents waiting across the road from the apartment in the evacuation zone shows a number of them wearing masks.

The notice also stated that NSW Health was yet to formally contact the strata management and advise them of the status of residents and visitors to the complex.

Further comment on the cases in the Gladstone Avenue complex is being sought.

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