In a poll of 15 patrons at three hawker centres, 12 customers noticed the awards displayed at several stalls, but none of them knew that these were paid advertisements.

Four of them said they were undecided about what to eat and the awards swayed them to try the food.

A taxi driver who was having lunch at Redhill Food Centre, and who only gave his name as Mr Lim, said: "I tell foreigners who take my cab to use the Michelin guide, and not to rely on such awards."

Food blogger Leslie Tay said there is nothing stopping people from promoting hawker food online but added that there is a clear line between promoting something and giving paid endorsements to hawkers. "Some hawkers are driven by competition to do this because they want to stand out," he said.

He added that awards will "definitely draw people's attention", the same way some restaurants promote their links to famous outlets like the black pepper crab eatery in Joo Chiat.

For now, paid advertisements on websites appear to have found a loophole as there are no rules that regulate their content.

"The legality and legitimacy of the awards given by private organisations is outside the scope of the advertising code," said Advertising Standards Authority of Singapore chairman Tan Sze Wee.

The Singapore Tourism Board, in an e-mail reply, said it has not received any feedback or complaints from visitors about food awards.

Mr Seah Seng Choon, executive director of the Consumers Association of Singapore (Case), said the awards may give consumers the impression that the eatery has won an award for the excellent quality of its food.

He said: "Consumers should be diligent and do their own checks to ensure that such awards are endorsed by recognised and legitimate agencies."

The National Heritage Board, which regulates the use of national symbols, said while individuals and organisations do not need the board's permission to use the popular symbol of the Singapore lion head, it will take action against those who abuse it.

In an e-mail reply, the board said: "While Singapore organisations may use the lion head symbol as a means of identifying themselves with Singapore, the public should not assume or take it to indicate any kind of official endorsement of the organisations' products or services."