Melbourne, Mar 15 (IANS): A quarantine hotel in the Australian state of Queensland has been placed under a lockdown, with genomic sequencing showing the likely spread of Covid-19 between overseas travellers.

Last week, a local doctor had tested positive for the B117 strain of virus after treating two patients who were transferred from the hotel to a nearby hospital, Xinhua news agency reported on monday.

Subsequent testing showed another guest who had been quarantining in a different room at the hotel had the same variant of the virus, raising the likelihood of further spread within the hotel.

Deputy Chief Health Officer Sonya Bennett explained that the whole genomic sequencing had confirmed the likely spread between guests at the hotel.

"The whole genomic is what we call a match between the three cases," Bennett said.

Testing was continuing to determine the extent of the outbreak, however as of Monday all hotel staff had been tested and they were all negative.

Queensland officially recorded six new cases of overseas-acquired Covid-19 on Monday, none of which were from the affected hotel.

Meanwhile, in the state of New South Wales (NSW), officials confirmed that a locally acquired Covid-19 case was also the B117 strain, as efforts continued to avoid further community spread.

The infected person worked at two quarantine hotels in Sydney as a security guard and visited several public venues while potentially infectious.

As a frontline worker, the man was among the earliest to be vaccinated in Australia, receiving his first dose on March 2.

However he is yet to receive a second dose.