Indian government officials have confirmed that the website of the Central Bureau of Investigation (CBI) was downed late last week.
The hackers, calling themselves the "Pakistani Cyber Army", said the attack was in revenge for similar Indian attacks on Pakistani sites, local reports said.
The border dispute between India and Pakistan over Kashmir has often moved online, with both sides attempting to hack each other's sites.
Roger Rawlinson, managing director of Assurance Division at NCC Group, said the attack highlights the importance and difficulty that governments face in keeping their digital assets secure, especially when they are susceptible to attack from potentially hostile neighbours.
"While these attacks are to humiliate rather than cause damage, a more serious attack, that denies a nation of electricity, communications and financial services, would have serious implications for its economy. The exploitation of vulnerabilities in central infrastructure is increasingly being considered during conflicts," he said.
According to Rawlinson, it is not only developing world countries that are at risk either.
"Developed world countries, including the UK, are much more prone to hostile incidents as they increasingly rely on business-critical online services to operate, making them a more appealing target. This was apparent when the UK's Navy website fell prey to hackers in early November," he said.
This story was first published by Computer Weekly