A NSW Health physician says the department decided not to wait for COVID-19 swab results before allowing the Ruby Princess to disembark because passengers needed to catch flights.

Dr Sean Tobin, the state’s chief human biosecurity officer, made a series of concessions at a special inquiry into the cruise ship, which was Australia’s largest source of coronavirus infections, on Tuesday.

When the Ruby Princess docked at Sydney’s Circular Quay in March, about a dozen COVID-19 swabs had been taken but 2600 passengers were allowed to disembark as the samples were taken to a lab.

Dr Tobin was pressed on why that risk was taken by public health administrators, given the inconvenience to passengers of waiting for the results would have been a matter of six hours or so.

The Ruby Princess, with 1000 crew on board, spent a fortnight docked at Port Kembla.

Commissioner Bret Walker SC said it could not have been about money, nor the commercial interests of cruise ships.

“By elimination I’m left with a question mark. What is it that was weighing against ‘waiting and seeing’?” the commissioner asked.

“I think it was a concern for the passengers primarily,” Dr Tobin replied.

“What, so they could get home, to their own bed?” Mr Walker asked.

“Well, to their flights,” Dr Tobin said.

Ruby Princess passengers boarded at least 10 flights for their onward travel, which then became the subject of contact tracing.

The Ruby Princess went on to become Australia’s largest single source of coronavirus infections and has been linked to at least 22 deaths.

Dr Tobin was part of a panel that assessed the ship as being “low risk”, despite signs of illness on board, which meant there was little intervention from health officials at the dock.

The department had been issuing the cruise ship industry with protocols in the earlier stages of the pandemic, including the recommended number of swabs on board.

The inquiry heard that earlier in March it had become obvious cruise ships had difficulty sourcing them. Dr Tobin said this reflected a global increase in demand.

But he also conceded little was done to change the apparent tolerance of ships flouting the recommendations.

The inquiry also heard in draft protocols written in February, NSW Health did not include any safeguards against the emerging possibly of COVID-19 transmission from those who were asymptomatic.

Dr Tobin said he was aware of the phenomenon and it was considered but not included in the draft document.

“You took it into account but decided to do nothing about it, is that right?” Mr Walker asked.

“Yes,” Dr Tobin replied.

The inquiry was shown an undated, anonymous review of the department’s Ruby Princess risk assessment, which Dr Tobin was emailed to check over.

Mr Walker suggested there was “distracting PR” and “spin” at play in the report, which suggested the assessment considered the risk of cross-infection if passengers were left on board.

Dr Tobin admitted this was not part of their thinking.

The inquiry continues.

-ABC