Batam naval base commander Colonel Muhammad Faisal said this has been going on daily for the past three years, according to a report in the Jakarta Post on Thursday.

Two men were arrested for cash smuggling during a raid in Batam on Wednesday, said the report, which did not give their nationalities.

The two, identified as Yong Peng and Toni, were caught red-handed carrying a total of 686 million rupiah (S$107,388) on board a ferry headed for Singapore.

The Indonesian immigration law forbids travellers from carrying more than 100 million rupiah outside the country.

'They admitted that the money was supposed to be delivered to someone in Singapore,' Col Faizal told reporters.

Col Faizal said navy investigators were still questioning the two men as they believe that such practice was also being carried out by many other smuggler groups.