Updated 11.13am: An Auckland mother has lashed out at The Warehouse after her 11-month-old daughter drank expired infant formula.

Keerthana Yogendran, 26, says she bought the formula last Wednesday.

When her daughter Joanna came down with a fever ,vomiting and diarrhoea, she became suspicious of the product.

It had expired four months earlier.

The child took several days to return to normal health and didn't have any formula for a week.

However The Warehouse says there's no way to prove or disprove a mother's claim she bought infant formula which had gone past its expiry date.

The Warehouse says staff checked for other expired stock, but couldn't find any.

The mother has been offered a full refund for the product and a gift card.