A hotel security guard who tested positive to COVID-19 is believed to have acquired the virus from a returned traveller who had been in the US.

The guard was working at a hotel quarantine at the Marriott Hotel at Circular Quay.

He worked at the hotel on August 3, 4, 7 and 8.

NSW Health contract tracers “identified a large number of possible exposures”.

While infected, the security guard has worked at or visited the Parramatta Local Court on August 11 and 12, Bankstown Central Shopping Centre on August 8 and Sydney Markets at Flemington on August 9.

NSW Chief Health Officer Dr Kerry Chant said he developed symptoms on August 11.

“We appreciate the co-operation of the individual, in giving us the history of where he’s been, he’s been very cooperative,” she said.

2GB reporter Clinton Maynard told Jim Wilson contact tracers have been looking at genome sequencing over the last 36 hours.

“It’s emerged a traveller who had been to America had stayed [at the hotel] and that traveller has since moved on to a hotel for sick patients.”

He said it has been established the strain of COVID-19 is not the same as the strain in Sydney’s south-west.

The health department is reviewing CCTV footage to understand how the guard contracted the virus, although there’s no suggestion he acted inappropriately.

It’s understood he took necessary precautions and was wearing protective gear.

Dr Chant said he could have acquired the virus either “directly from the individual” or via an intermediary”.

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Image: Channel 9