And penalties for importing them without permission can be harsh.

Police last year investigated about 70 cases involving pellet guns, which look like real firearms and fire pellets at high speeds.

This figure is nearly double that in 2006, when 38 cases were investigated.

Just last month, a man was fined $15,000 after he was found with 20 pellet guns and plastic pellets in his luggage on arrival at the Budget Terminal.

The 58-year-old businessman apparently intended to sell the guns - which looked very much like real weapons, complete with laser attachments and silencers - here.

But the law is clear: Individuals are banned from possessing pellet guns, also known as airsoft guns.

Not only can pellet guns cause injury when fired improperly, but as they look so much like real firearms, they can also be used to commit criminal acts.

As a general rule, all toy guns must be approved before they can be brought into Singapore.

But people have been known to try and bring in prohibited fake guns through the airport and checkpoints. Others try to use the mail.

A police spokesman advised travellers who possess such items to declare and surrender them at the immigration checkpoints.

'This is to avoid a situation where police seize the items and initiate investigations against the traveller, as the items were not declared even after the opportunity to do so had been given,' he said.

To pass muster, toy guns are examined for their resemblance to actual firearms and their likelihood to cause harm when pellets are fired.

For example, a bright plastic gun without pellet magazines or a movable slide - the top part of a pistol that is pulled back to load rounds - is likely to pass the visual check.

But if during a firing test, it is found to shoot pellets at speeds so high that there is a 'probable risk of hurt', then it is likely to be banned.

Failure to meet either of these criteria means the toy gun is unlikely to get the nod.

Approval can come in the form of letters or verbal confirmation by police licensing officers, or even verbal approval by officers at the checkpoints, the police said.

If he is unsure, the checkpoints officer will refer the toy gun to a licensing officer for an assessment.

Toy importers contacted say they are well aware of the stringent regulations, and that they are careful about the type of toy guns they bring in for sale here.

A manager at Lian Thye & Co said: 'The guns we import all look fake in terms of size, scale and design. They are battery-operated and emit sounds, not pellets.'

In any case, toy gun sales are no longer the roaring business they used to be, said the manager, who gave his name only as Mr Lim. He has been in the trade for over 20 years.

Compared to a decade ago, toy gun sales for his firm have dipped by up to 80 per cent.

'Kids nowadays don't have much interest running around pointing guns at each other.

'They would rather play virtual shooting games on computer screens,' he said.

joolin@sph.com.sg

ADDITIONAL REPORTING BY KARAMJIT KAUR

PASSING THE APPEARANCE TEST

'The guns we import all look fake in terms of size, scale and design.' MANAGER AT TOY IMPORTER LIAN THYE & CO