A 63-year-old is accused of flouting a suppression order relating to the British backpacker's killer, Detective Inspector Scott Beard confirmed to the Herald in a statement today.
He is the first person to be charged by New Zealand police after numerous suppression breaches before and after last month's high-profile trial.
The man has been summonsed to appear in the Auckland District Court next month.
Meanwhile Millane's killer will return to court on February 21 to be sentenced.
Just moments after a jury found the 27-year-old man guilty of murdering the British backpacker on November 22, the presiding judge, Justice Simon Moore, said the killer's name would remain suppressed "until further order of the court".
The reasons for the order and the legal arguments made by both the Crown and defence have also been suppressed.
Beard, the police officer in charge of the case, warned Kiwis about breaching suppression orders relating to the case just a day after the guilty verdict.
"While we appreciate the public feeling around this case, we do want to remind the public that it is an offence to breach a court order such as a name suppression - this includes naming someone on social media," he said.
However, breaking a suppression order is not an extraditable offence, those who do so overseas are beyond the reach of New Zealand law.
But people in New Zealand who are found to have breached suppression face up to six months' imprisonment or a $25,000 fine.
In the case of a company breaching, a fine of up to $100,000 can be imposed.
The recent breaches, largely by those here and the United Kingdom, come after a year of debate about the effectiveness of New Zealand's suppression orders in the internet age.
After Millane's killer first appeared in court last December, British media named him in its papers, online and on-air.
The Herald later reported two UK newspapers' explanations for naming the accused, after objections were raised by a close friend of the Millane family.
"Whilst [the publication] takes into consideration the laws of other countries when it comes to naming suspects/those charged with a crime and the names of victims of crimes we should stress that the law in New Zealand does not apply to our reporting," one broadsheet replied to a complaint.
Internet behemoth Google also breached a suppression order when it named Millane's then accused murderer in its "what's trending in New Zealand" mass email to New Zealand subscribers.
The email said there had been more than 100,000 searches on its search engine of the man's name.
The Google breach was met with condemnation by Justice Minister Andrew Little, who held a meeting with Attorney-General David Parker and executives from the Silicon Valley-based company.
In July, Google suspended its trending emails in New Zealand and apologised to Little.
After the High Court trial, Little said the breaches were "really disappointing" but was optimistic changes to the way court suppression orders were enforced were on the way.
Little has started work with his counterparts in the UK, Australia and Canada to see what more could be done to ensure suppression orders were obeyed, but "it'll take a couple of years".
