Singapore: A 36-year-old Indian-origin man has been jailed for four years and eight months on charges of hacking computers of at least seven organisations including the ruling party in 2013.

James Raj Arokiasamy, who calls himself "The Messiah", had pleaded guilty to the charges last week, The Straits Times reported today.

He used software to scan various government servers including those of the Prime Minister's Office and Elections Department as well as Peoples' Action Peoples' Action party (PAP) Community Foundation, a town council and the City Harvest Church, the management of which is on trial related to fund management.

Many of the sites were defaced with taunts and threats, the report said.

Raj had also hacked a Straits Times blog, and illegally accessed a server that contained bank statements of Standard Chartered Bank clients.

He had displayed "audacious bravado" in his acts, which had caused public alarm and fear, said Deputy Presiding Judge of the State Courts Jennifer Marie.

James Raj used specialised software tools to avoid detection which was a high degree of premeditation, planning and sophistication, the judge said.

Police had spent more than 2,465 man-hours to investigate the cyber attacks, he added.

Having discharged his defence lawyer at the start of the proceedings yesterday, Raj submitted an additional plea to the court, contending he had not acted maliciously.

But the Judge agreed with the prosecution that his cyber intrusions were not amateurish nor committed naively.

"His intention? was to instill fear and trepidation. Given the current climate where international and domestic terrorist security threats a more prevalent than before, a threat to the IT systems (and) cyber attacks in a highly networked country like Singapore should be visited with exemplary sentences," the Judge said.

Raj had also pleaded guilty to drug consumption. A further 119 counts of computer misuse, and two other drug offences, were considered in the sentencing.

For each of his proceeded counts of illegally modifying the contents of a computer system, he could have been jailed for up to three years and fined up to Singapore dollars 10,000.