Singapore's consumer watchdog is making e-commerce complaints one of its top priorities as more consumers approach it with cases of defective goods or undelivered purchases.

The Consumers Association of Singapore (Case) received 636 complaints related to e-commerce last year, up from 523 in 2015 and 485 in 2014.

The spate of online purchase scams also led the police to post a reminder on its Facebook page last month reminding members of the public to guard against such ploys during the festive season.

A survey by business consultancy PwC last year showed that 60 per cent of consumers in Singapore buy products online at least once a month.

Consumers already have some form of recourse under the "lemon" law, which falls under the Consumer Protection (Fair Trading) Act.

Under this Act, buyers of goods and services sold online by a registered Singapore company can make a claim for a defective product within six months of purchase. They can exchange, repair or seek a refund from the retailer.

However, without a physical presence, many of these errant online retailers - some of whom may be based overseas - are difficult to track down.

New Case executive director Loy York Jiun's strategy to work with trading platforms with a presence in Singapore instead would be an important step to protect consumers.

Middleman trading platforms are ultimately able to hold on to payments to retailers until customers indicate that all is well with the products they have received. This will save consumers and the authorities the time-consuming and expensive process of trying to track down a seller who may not even be bound by Singapore's laws.

However, until such an agreement with middleman platforms is achieved, consumers should exercise their judgment before making an online purchase and look for reputable sellers and payment options.

If a deal seems too good to be true, it probably is.