Constable Darren Critchley thought his working day was over at 4pm on Wednesday.
The Highway Patrol officer works out of Kaitaia, and was heading home to Houhora, ready to log off for the day.
Suddenly his police radio delivered the news of an emergency on 90 Mile Beach.
He headed for the beach, not far off the end of Hukatere Road, about 10 kilometres away.
"I attended a drowning in the same place two years ago, and, being a local and aware of the real dangers associated with swimming on this part of 90 Mile Beach, I deemed it serious enough to offer assistance," he said.
Witnesses on the beach told Mr Critchley two people were in the water, although he could only see one, about 100 metres off the beach.
"The sea was very rough, with two-metre waves breaking more than 100 metres out."
With the fire brigade 25 minutes away, and a rescue helicopter 35 minutes away, Mr Critchley, an accomplished swimmer, made the decision to go into the water.
"Although the sea was treacherous I believed I had a chance of being successful."
Paul Desmond, owner of a nearby backpackers' accommodation had attempted a rescue but returned to the beach exhausted.
Mr Critchley borrowed Mr Desmond's life jacket and surfboard and entered the water.
"The sea was a mass of foam," he said.
"I was getting smashed. The waves kept forcing me back. I remember looking back to shore and being guided to the exact location of the male I was trying to rescue. I still couldn't see a second person."
He finally reached the man, who was exhausted and distressed.
Mr Critchley got him safely to land, before heading back into the surf, where he found a young woman, face down and unconscious.
"I don't have a real concept of time at this point, but it felt like 10 minutes before I finally made it to shallower water, and I again gave her two breaths."
A fire brigade crew that had arrived by that time began CPR, while an exhausted Mr Critchley was treated by a St John crew.
Sadly the woman, from Germany, died. The man Mr Critchley had saved was also from Germany.
It is the second time Mr Critchley has risked his life for others.
In 1991, shortly after he joined the police force in his native England, he went into a Lancashire river to try to save a 14-year-old boy.
He was able to retrieve the teenager's body. "It turned out quite some time later that it was a homicide."
Mr Critchley's heroism was recognised with the Liverpool Shipwreck Society Award.