The prime minister’s office email system was under the grip of a computer virus for three months last year, forcing officials to replace the software. The technical glitch plagued the email system, based on Microsoft Outlook Express, from February to April in 2008.

Although the extent of damage is uncertain, the PMO said most emails addressed to it were not received.

The problem was detected only late April, after which the software was replaced.

The matter came to light when the Central Information Commission heard a plea of retired air commodore Lokesh Batra, who had complained to the PMO in an email about discrepancies in the Hindi version of the right to information act, circulated by the department of personnel and training.

“What is surprising is the fact that otherwise prompt IT experts posted in the PMO failed to diagnose the problem for three long months,” an IT expert said.

Central public information officer Amit Agrawal submitted before chief information commissioner Wajahat Habi-bullah, “In view of... the technical problem mentioned above, it is clear that the events presumed to have taken place or documents presumed to have been in existence did not take place or get created.”