SINGAPORE - A principal tax auditor with the Inland Revenue Authority of Singapore (Iras) logged on to his workplace computer system and unlawfully changed its contents by increasing the amount of cash payout meant for his mother's firm by $30,000.

The company, known as XLN Holdings, had taken part in the Productivity and Innovation Credit (PIC) scheme run by Iras.

The scheme offered tax deductions or cash payouts to firms that had made investments to enhance productivity and innovation, such as by investing in staff training, information technology or automation equipment.

The principal tax auditor, Neo Haw Yng, who was from the agency's Compliance, Clubs, Trust and Gaming (CCTG) Branch, went on the Inland Revenue Interactive Network (IRIN) at around 10.40am on Feb 10, 2015, and changed the payout amount from $4,881 to $34,881.

However, his crime was uncovered and Iras did not disburse the amount.

Neo, 32, was jailed for three months and four weeks on Friday (May 3) after pleading guilty to three charges under the Computer Misuse and Cybersecurity Act. The Straits Times understands that he is no longer with Iras.

Deputy Public Prosecutor Thiagesh Sukumaran told the court that Iras uses IRIN to manage Singapore's tax system.

He added that Neo started working for Iras in November 2010 and was posted to the CCTG Branch of the Corporate Tax Division about four years later.

As part of his duties, he processed PIC cash payouts to companies. However, he was only authorised to do so when his supervisor assigned a case to him.

Despite this, Neo was at his Revenue House workplace in Newton Road on Feb 10, 2015, when he went on IRIN and, on two occasions, accessed without authority the company account of a firm known as XLN Studios.

The court heard that his mother was the director of both the company and XLN Holdings, while Neo ran their operations.

He later increased the PIC cash payout for XLN Holdings at around 10.40am that day.

The next day, the Assistant Commissioner of the Corporate Tax Division alerted the CCTG Branch director on a possible misuse of the IRIN system linked to PIC payouts.

DPP Thiagesh said: "This involved an application by a company named XLN Marketing. During the course of assessing the application, Iras noticed that there were documents signed off by one 'Patrick Neo' who was listed as the general manager of XLN Marketing."

As the name on the documents closely resembled Neo's, Iras then conducted an internal investigation and uncovered his offences.

For accessing a computer system without authorisation, first-time offenders can be jailed for up to two years and fined up to $5,000.

Repeat offenders can be jailed for up to three years and fined up to $10,000.