"As an extra precaution and following similar advice from public health authorities in Australia, customers should cut up any Australian strawberries before eating them," it said.
"Countdown is in contact with both New Zealand and Australian authorities as they investigate this matter."
Asked specifically about which Countdown supermarket store the affected strawberries were found at, a spokeswoman would not say.
It is not known either whether the affected punnet was discovered by a member of the public or a staffer.
The spokeswoman told the Herald that apart from this discovery, no other strawberries with needles had been reported across the Countdown store network in New Zealand.
Foodstuffs said last week that it would halt the distribution of Australian strawberries in New Zealand.
Foodstuffs operates Four Square, New World and Pak'nSave.
Auckland resident Ly Nguyen was alarmed to hear about the discovery of needles in strawberries sold by Countdown.
She emerged from Countdown's city outlet on Victoria St with a bag full of fruit and veges but had not bought any strawberries.
She said she ate the fruit often but usually in the summer when it was in season.
"I have never heard of an incident like this with Countdown," she said.
"It is a worry this can happen in New Zealand.
"Now we have to make sure that every time we buy strawberries it is safe."
Although more an apple guy, student Atish Bhattarai ate strawberries occasionally and said he was also concerned.
He also said this should not be happening in New Zealand and hoped authorities investigate.
"But Countdown can't check all its strawberries so the main responsibility is with the company that packed them," he said.
Police said they received a report on Sunday about a person finding needles inside strawberries they had recently purchased.
"Police are taking this report seriously and are investigating together with our colleagues at the Ministry for Primary Industries," a spokesperson said.
"The person who reported the incident was not harmed as the needles were found before anyone had eaten them."
Anyone who finds anything suspicious in their food is asked to contact police immediately.
The find comes after a huge recall across the Tasman, where the product was pulled from the shelves of several supermarkets when strawberries spiked with needles were discovered across six regions in Australia.
Queensland police are leading an investigation into the source of the needles, and the state's Premier, Annastacia Palaszczuk, has stumped up a reward of $100,000 for anyone with information that leads to the capture of the culprits.