Countdown supermarket inserted an unfortunate typo in a sign advertising biscuits at its Meadowbank store in Auckland.

Supermarket chain Countdown has apologised for an "unfortunate case of human error" that led to an embarrassing typo on one of its in-store signs.

The sign advertising Griffins Krispie Toasted Coconut Biscuits misspelled the word coconut, turning it into an offensive expletive.

The mistake, which happened at Countdown's Meadowbank store in Auckland on Tuesday, led to a social media frenzy with a photo of the sign posted on Countdown's Facebook receiving more than 7000 likes and almost 1500 shares.

The Facebook post also inspired a stream of comments about other amusing typos spotted on signs and jokes about the misspelling.

A Countdown spokeswoman said a customer alerted store staff to the mistake on Tuesday.

The sign was taken down immediately and no formal complaints were received, she said.

"This was simply an unfortunate case of human error and we apologise for any offence this has caused our customers."