Hackers have attacked Hunting & Fishing's website, forcing the company to keep it closed and issue a warning to customers about suspicious transactions.
The attack on the site was detected earlier this month and it remains closed today.
In a notice on the site, the firm says customers who had bought any goods online should contact their bank and check transactions
"We suggest you do this at the earliest opportunity."
General manager Trent Smith said the situation remained as it was last week when it was reported there had been around 20 suspicious transactions, although nobody had appeared to have lost any money.
"I think the banks have been pretty good with customers - it's all in the hands of the banks and Visa," he said.
The notice says the website was created and operated by certified service providers "with what we understood to be the best security provisions available.
"So naturally we are alarmed as you will be too over what has happened."
Hunting & Fishing has stores throughout the country which were not affected but Smith said the attack has hurt the business through the website.
"Hopefully it will be live again soon."
Although New Zealand's rate of cyber attacks is low compared to other countries in the region, Microsoft said at a recent Singapore conference that they were happening constantly.
For a week in April the company recorded one and a half million New Zealand devices infected with malware, or malicious software.
The highest concentration of malware was in Auckland, followed by Tauranga and Wellington.