The city of Mumbai, India, was deprived of Rs 35,000 crore ($7.5 billion) in tax over a five-year period due to a faulty IT system, according to a report in the Hindustan Times.

The system was supposed to transfer data collected by the Central Information Branch of India’s tax department about "high spenders and investors" to regional tax offices, the newspaper reported today.

"However, a non-functional computer system and lack of training to officials in handling the system [meant] the relevant information was not disseminated thereby causing a huge revenue loss to the department," it claims.

This information was not transferred via the computer system from 2005 until 2010. Some data was transferred in 2006 using CD-ROMs, a method that had been banned in 2003.