After two weeks of investigations, the Consumers Association of Singapore (Case) has revealed that several supermarkets are illegally selling chocolate bars without expiry dates.

Several brands of chocolate sold for the Christmas season were found to be without the mandatory expiry date, including Nestlé's Winter Wobblers, and Palmer's Beary Merry Christmas and Santa's Workshop.

Stephen Loke, chairman of Case's consumer affairs committee, told the Straits Times: "This is an infringement of the law." He added that shoppers should be wary of consuming chocolates with expiry dates that are a couple of weeks away.

Nestlé Singapore, the local arm of the Swiss behemoth, has admitted that it made a mistake in failing to put date stamps on the chocolate products. The firm explained that the chocolates "have very clear expiry dates on the main outer cartons, but an oversight occurred by not providing a duplicate marking on each individually-wrapped pack".

Nestlé added that the chocolates are due to expire in April and May next year.

The supermarkets responded to the news by confirming that some of these chocolates were sold inadvertently, and that investigations would be launched to discover how they had ended on the shelves.