An Indian hacker broke into the Royal Australian Air Force website and defaced it with a threatening message aimed at the Australian government, the Sydney [Images] Morning Herald reports.

The Department of Defence confirmed that the hack took place between Monday and Tuesday, forcing it to pull the entire RAAF website offline and replace it with a page explaining that there had been 'technical difficulties'.

The site has now been restored, the paper said.

While the department would not reveal who perpetrated the hack, Indian television channel Times Now reported the message warned the Australian government to stop attacks on Indian students or else face further cyber attacks.

The message read: 'This site has been hacked by Atul Dwivedi. This is a warning message to the Australia [Images]n government. Immediately take all measures to stop racist attacks against Indian students in Australia or else I will pawn all your cyber properties like this one.'

A Defence spokeswoman said the RAAF website was not used to conduct official air force business and no sensitive information had been stolen.