The auction was held about a day after the couple arrived on a direct flight from Guangzhou in southern China.

The pair, aged 60, have since been admitted to the Royal Adelaide Hospital where they remain in a stable condition in isolation.

SA Health officials are now trying to contact other people on the same China Southern Airways flight that arrived on January 21.

The real estate agent has also provided authorities with a list of people who attended the auction on January 22 and its office remain closed until Thursday.

Meanwhile, an Adelaide couple on a cruise through Asia say they have been "rejected again" and are feeling unloved after the Holland America liner was denied entry to several scheduled ports due to the coronavirus threat.

Grandparents David Holst and his wife Judy are on Holland America's MS Westerdam, which entered Hong Kong on Saturday resulting in a planned stopover in Manila being cancelled when authorities denied the boat entry.

Mr Holst posted on Sunday on his Facebook page, "It was greed and stupidity when Holland America sent our ship into Hong Kong yesterday given HK is on red alert, the highest level you can have around the virus and other cruise lines were cancelling HK stops as HK is the gateway to China".

He said the crew "did not even bother to offer face masks to passengers going ashore" so they disembarked using their own and they "did not see any temperature screening for those 700-800 joining the cruise".

He described sanitation prevention on the liner as "ordinary" and said they were not amused as it was totally avoidable if Holland America had acted "more responsibly".

Mr Holst said planned stops at Hualien in Taiwan on Tuesday had now also been cancelled, but the liner was heading to Kaohsiung further south on Wednesday.

He said there were "plenty of Aussies" on board, including others from Adelaide and criticised the cruise company for only really caring "about dollars".

Hong Kong has recorded 15 confirmed cases of coronavirus.

Australian Associated Press