SINGAPORE - A telecommunications retail shop owner was jailed for six months on Wednesday for fraudulently registering pre-paid SIM cards.

Tan Chinn, 38, admitted to seven of 20 charges under the Computer Misuse and Cybersecurity Act. The offending period was from April 2013 to February last year.

Between December 2013 and January last year, police were investigating cases of fraudulently registered pre-paid mobile lines used by unlicensed moneylenders. Many of these pre-paid mobile lines had been registered under the identity of local subscribers with no known connections to loansharks.

Investigations revealed that many of those pre-paid mobile lines had been registered by Tan Mobile, which he had been running since 2006.

Tan, who was arrested in February last year, admitted to pre-registering SIM cards and selling them.

The court heard he committed the offences using a pre-paid SIM registration machine from each of the three telcos - StarHub, M1 and Singtel.

He would scan the identity card number or passport of a customer, linking the identification details of the customer with the particular pre-paid mobile line.

Some time in early 2013, he began pre-registering SIM cards using the details of unsuspecting customers. He would then sell theses cards to those who did not have their work permit with them or to other persons who specifically asked to remain anonymous.

These fraudulently pre-registered SIM cards would also count towards the sales quotas set by the respective telecommunications companies, resulting in monetary incentives for Tan.

Tan knew that his actions would modify the contents of a computer and were unauthorised.

Investigations showed that some of these pre-paid SIM cards had been linked to unlicensed moneylending activity.

Tan's lawyer Choo Si Sen said in his mitigation plea that his client's main motivation for registering the extra pre-paid SIM cards was to meet a sales quota which, when met, would bring him benefits such as trips abroad. Tan could have been fined up to $10,000 and jailed for up to three years per charge.