A man has contracted COVID-19 after dining at a Sunnybank restaurant where a woman at another table had the disease without knowing she was contagious.

The woman is one of three whose failure to quarantine after a controversial trip to Victoria has sparked Queensland’s most dangerous COVID-19 cluster in months.

The man, 27, from Bellbird Park, is now being treated in quarantine after testing positive to COVID-19 overnight. He is the fourth case in a cluster sparked by the three women who travelled to Melbourne for a party, allegedly breached border controls, and were active in south-east Queensland for a week before the alarm was raised.

Two of the three women, both 19, tested positive to COVID-19 and one infected her sister, a 22-year-old woman. That led to the closure of two schools, various businesses, and a lockdown at 94 aged care facilities.

One of the infected 19-year-olds attended the Madtongsan IV Restaurant for dinner on July 23. Contact tracing, public health alerts and ramped up testing led to the Bellbird Park man returning a positive diagnosis overnight.

The man, his wife and her sister had dinner at the restaurant on the same night as the 19-year-old. The wife and sister have also been tested but results were not available on Friday morning.

Queensland’s Chief Health Officer, Jeannette Young, said it was “highly likely” one or both of those test results would also come back positive.

“This is very, very early information and it could rapidly change,” Young said.

Young again urged anyone who had symptoms to get tested and said contact tracing would continue.

“At any point in Queensland today we could have cases pop up,” Young said.

One of the women being tested works at the Bolton Clarke aged care facility in Pinjarra Hills, which has taken extra precautions in the event she has also been contagious.

Queensland Health identified some 1500 potential contacts at risk of becoming part of the cluster.

Deputy Premier Steven Miles said 9076 tests were done on Thursday and health authorities were trying to process people faster to reduce delays.

“We broke records yesterday in Queensland for our level of testing,” Miles said.

Premier Annastacia Palaszczuk urged Queenslanders to remain vigilant, especially if they had attended any of the premises that had been subject to a health alert, such as the Sunnybank restaurant.

“We’re not out of the woods yet, we’re going to keep a very close eye on what’s happening, especially over the next few days, but the response has been terrific,” Palaszczuk said.