The Defence Ministry will file a complaint with Delhi Police tomorrow against unknown persons for sending fake e-mails to media organizations and government officials on its behalf using fictitious email-IDs.

"An advisory has been issued to not open or use contents attached to these fake mails generated through fictitious email-IDs. We are lodging a complaint with Cyber Cell Unit of Delhi Police to investigate the matter," a senior Ministry official told PTI here today.

The fictitious IDs which were used to send these mails over the past two days bore close resemblance to the ones used by the ministry itself to send emails to media organizations and government offices, the official said.

The IDs which were used to circulate the mails were '[email protected]', '[email protected]' and '[email protected]'.

The mail from the last two email addresses claimed to contain "Information on Anti-Piracy Operations" of the Indian Navy and was circulated on the night of March 29.

The second fake mail on "The minutes of the secret meeting between India and Pakistan", sent from e-mail ID '[email protected]' was sent this morning and claimed to contain information of secret Indo-Pak meetings on Kashmir.

The fake mails have also forced the Navy to revert back to the email-ID provided by National Informatics Centre (NIC) from the one they had earlier registered with Gmail.

A similar incident was reported in the Defence Ministry a year ago, when fake mails claiming to have secret information on Chinese military establishment were circulated.

"Those mails were programmed to launch encrypted cyber worms which could steal information from computers. It is a very common form of cyber attack practiced by China and Pakistan," an official privy to the information said.

This time, though officials are denying any form of cyber attack, the matter has been reported to the concerned agencies.

"It is a matter of national security. We want to assure that such things do not happen again," officials said.