One year since the body of British backpacker Grace Millane was discovered in dense bushland on the outskirts of Auckland, the man accused of murdering her is standing trial in Auckland.

The 27-year-old New Zealand man re-entered his not-guilty plea in proceedings on Monday. He was granted name suppression by the high court in Auckland in December. The five-week trial will resume on Wednesday, with a 12-person jury comprising seven women and five men, RNZ reported.

Justice Simon Moore noted the case was the subject of intense public and media interest, and warned jurors to leave emotion at the door. Moore also noted that politicians – including the prime minister – had “waded into the debate” of Millane’s death in New Zealand during her overseas experience.

“Her disappearance, followed by confirmation of her death, excited intense media attention and public comment both here and overseas. Vigils in her memory were held across the country and there were marches and other public events.” Justice Moore said.

“No one in this country, unless they were out of all communication with the modern world, could not have been aware of these events. The story took the nation by storm and that interest continues today, which is plainly evident from the banks of media present here.”

“Every juror has a duty to put feelings of sympathy and prejudice to one side and approach their task coolly and dispassionately.”

Forty crown witnesses will give evidence in Auckland high court, RNZ reported, including Millane’s father, David.

Millane, 21, disappeared from central Auckland on 1 December and her body was found in bushland in west Auckland a week later.

The death shocked New Zealand and prompted an outpouring of public grief.

The prime minister, Jacinda Ardern, made an emotional public statement, saying Millane should have been safe visiting Aotearoa.

“There is this overwhelming sense of hurt and shame that this has happened in our country, a place that prides itself on our hospitality, on our manaakitanga,” Ardern said, using the Māori word for hospitality.

“So on behalf of New Zealand, I want to apologise to Grace’s family – your daughter should have been safe here and she wasn’t, and I’m sorry for that.”

Unusually tight restrictions have been placed on local and international media reporting the case, after the accused’s name and photograph was published last year by several British newspapers, potentially jeopardising the crown’s case against him.

Members of the public also shared his name and photographs widely on social media platforms and blogs.

Mass candlelight vigils were held for Millane, who came from Essex, in every major town in New Zealand, and grief experts said many New Zealanders experienced “vicarious trauma” about the murder in the usually safe country, averaging fewer than 50 homicides a year in a population of 4.9 million.

Millane was travelling in New Zealand as part of a year-long overseas experience and was last seen alive on CCTV footage entering a hotel in central Auckland on the night she disappeared.

After her death Grace’s father, David Millane, spoke at a candlelit vigil held in her honour.

“Grace was not born here and only managed to stay a few weeks, but you have taken her to your hearts and in some small way she will forever be a Kiwi,” Millane said. “We all hope that what has happened to Grace will not deter even one person from venturing out into the world.”