Naval officials said it was "premature at this stage" to comment on the sensitivity of the compromised data which was discovered at the beginning of the year, a report by The Indian Express newspaper said.
A Naval Board of Inquiry is believed to have indicted at least six mid-level officers breached security protocol that could have led to the cyberattack, The Indian Express report said.
Naval computers were found to be infected with a virus that collected and transmitted confidential files and documents to Chinese IP addresses, although the navy would not confirm if that meant espionage as the reason for the attack.
India's Eastern Naval Command plans operations and deployments including sea trials of the country's first nuclear submarine, the Arihant.
Deployments of ships by the ENC are as far away as the South China Sea, an area where China is in several militarily tense territorial disputes with several countries bordering the sea.
"An inquiry has been convened and findings of the report are awaited," a naval officer said in response to written questions from The Sunday Express, a sister publication of The Indian Express.
"It needs to be mentioned that there is a constant threat in the cyber domain from inimical hackers worldwide."
The report said sources said there is a possibly that the virus entered the main computer system through the use of flash drives, sometimes called pen drives, although the navy prohibits the use of the small portable memory stick devices.
China has been accused before of attempting to hack into India's military computer systems.
In April 2010 a group of U.S. and Canadian computer security researchers monitoring a spying operation observed Chinese hackers as they pilfered classified and restricted documents from India's Defense Ministry.
The 2010 report by researchers at the Munk School of Global Affairs at the University of Toronto said it was possible hackers had entered computers of the army's new Shakti artillery combat and control system.
Also thought to have been compromised in 2010 was is the country's mobile missile defense system.
The report said hackers in Chengdu, western China, had access to documents sensitive reports concerning India's relations in West Africa, Russia and the Middle East.
The announcement of the latest cyberattacks come as maritime security issues, including cybersecurity, in the Asia-Pacific are increasingly important for India.
In May India's foreign minister S.M. Krishna hosted his Japanese counterpart, Koichiro Gemba in New Delhi for security talks.
The meeting was the sixth round of strategic dialogue between the two countries just before a joint naval exercise off the coast of Japan last month.
Their discussions also included the international fight against piracy, especially off the coast of Somalia and the Gulf of Aden, a Times of India report said at the time.
"India is actually situated at an important place on the sea lanes of the communication which links Japan with West Asia," said Gemba.
"So, I can't overlook the geo-political significance of the location of India."
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