Police have arrested 124 people in Tonga for offences that broke Covid-19 restriction rules put in place for a week long lockdown.

The lockdown was called for the main island of Tongatapu after a Tongan repatriating from New Zealand tested positive for Covid-19.

Strict rules were put in place but ended Monday, included the extension of an existing night-time curfew.

RNZ Pacific correspondent Kalafi Moala said authorities had not counted on people failing to follow the rules.

"There were 124 arrests. That includes 36 ... who held kava parties.

"That was not expected to happen. In the statistics they say that 43 people broke the law in terms of the curfew - violated the curfew time, and 19 people were getting together in gatherings, drinking alcohol."

The person who tested positive for the virus returned a weak positive result.

Moala said the infection scare helped hasten vaccinations, and 93 percent of adults have now had their first jab.