THEY are normally noisy, boisterous and jumpy. But officers from the Immigration and Checkpoints Authority (ICA) inspecting a consignment of live frogs in the boot of a car at Woodlands on Monday night found the amphibians too quiet for their own good. They were also lifeless.

This aroused their suspicion of the ICA officers, who decided to take a closer look.

Bingo! They found 44 cartons and 59 packets of contraband cigarettes hidden in the spare tyre compartment of the car boot.

The Malaysian man, 45, who had declared the consignment as 'live consumption frogs', and even exchanged greetings with the ICA officer earlier, was nabbed.

He admitted they were contraband cigarettes, for which he would have to pay $3,832 in customs duty and GST.

The man would get RM600 (S$251) on successful delivery of the contraband cigarettes to Singapore.

He later revealed that he was told to leave the car at Johor Bahru in the evening, and collect it 30 minutes later and also told to drive to Ang Mo Kio.

Singapore Customs is investigating the case.

First time offenders can be fined up to a maximum of 20 times the amount of duty evaded. For second or subsequent convictions, offenders can be jailed for up to two years, and fined. They also face further fines based on the amount of GST evaded.

In a statement, ICA said it has tightened security checks on passengers and vehicles at the checkpoints to prevent attempts to smuggle in undesirable persons, drugs, weapons, explosives and other contrabands.

"The same methods of concealment used by contraband smugglers may be used by terrorists to smuggle arms and explosives to carry out attacks in Singapore," it added.