Six overseas travellers who reported they were fully vaccinated have tested positive for COVID-19 while in hotel quarantine, authorities have revealed.

The numbers were released in this week’s NSW Health COVID-19 surveillance report as the federal government pushes forward with its vaccine passport plans.

The report states six people in the NSW hotel quarantine system tested positive over four weeks ending on May 1, despite reporting they were vaccinated prior to landing in Australia.

The figures raise concerns about the prospects of a vaccine passport system as Scott Morrison comes under increasing pressure to repatriate Australians stranded overseas.

NSW Health noted all six may have contracted the potentially deadly virus prior to their vaccination becoming fully effective.

The report stated a dose does not become fully effective until two weeks after the patient receives the second of a two-dose vaccine.

According to federal government figures 2.5 million Australians have received their first dose of the coronavirus vaccine.

But the government has received criticism for its slow roll out, falling well below its target of having four million adults given the jab by the end of March.

Prime Minister Scott Morrison this week said his government was working on a prospective vaccine passport system, which would allow those with the jab to travel more freely.

He noted a condition of such a system would be proof that vaccines protect travellers against the transmission of the virus.

The success of the rollout will play a big part in any planned vaccine passport system, which would allow Australians to travel abroad.

China unveiled its digital passport system last month, with other countries including the United States announcing similar plans.

It would allow travellers to prove that they had been vaccinated in order to enter another country.

“I think (a vaccine passport) is the next step, but I do think that next step is some way away,” Mr Morrison told 3AW.

“If you’re fully vaccinated, you would be able to travel, certainly around Australia, but maybe overseas, without the need for hotel quarantine.”

The report also reveals that 89 of the 180 cases came from overseas travellers arriving from India, followed by the United States (15) and Bangladesh.

India has been racked by the virus, prompting the government to ban anyone from travelling to Australia if they had been to India in the previous fortnight.

The ban will be lifted on May 15, Mr Morrison said.

He described the ban as a “pause” and said it would end on its intended date, with repatriation flights to begin after that.

They are currently 9000 Australians in India who want to come home, including 173 children who are in the country without their parents, a Senate committee heard this week.