Alleged death threats and online abuse against referees involved in 2023's Rugby World Cup in France are being investigated by police in New Zealand.

The acting director of the nation's National Criminal Investigations Group, Detective Inspector Stuart Mills, confirmed on Friday that three complaints had been received from governing body World Rugby about death threats against match officials allegedly made from New Zealand.

Police are investigating the alleged breaches of New Zealand's Harmful Digital Communications Act and the offence of threatening to kill.

According to a World Rugby report, 21 verified social media accounts originating in New Zealand sent threats or abuse to match officials or players who had been involved in the World Cup.

World Rugby said its forensic research analyst is working with police and enforcement authorities in Australia, South Africa, France, New Zealand and the United Kingdom to prosecute those responsible.

An Australian man has been charged and is due to appear in court in coming days, according to the Sydney Morning Herald.

World Rugby said eight match officials and 49 players received online abuse during or after the World Cup.

English referee Wayne Barnes sent-off All Blacks skipper Sam Cane in the tournament's final in October, which was won 12-11 by South Africa.

Barnes retired after the tournament citing threats and abuse towards himself and his wife.