Australia's most populous state has recorded more than 6,000 new Covid-19 cases for the first time, adding a sombre note to Christmas celebrations.

New South Wales reported 6,288 new infections over the past 24 hours, an increase of 676 cases from the previous day and by far the highest number of cases in any Australian state since the pandemic began, AP reported.

Victoria, Australia's second-most populous state, reported 2,108 new cases and six deaths.