Indian federal investigators say they have charged a former telecommunications minister in connection with the ongoing probe into one of the country's biggest corruption scandals.

The Central Bureau of Investigation raided the homes of Dayanidhi Maran and his media tycoon brother Monday.

Dayanidhi Maran, India's telecom minister between 2004 and 2007, is the second former telecom minister to be probed in a corruption case that has rocked the Indian political and business establishment. His successor, A. Raja, has been under arrest since February, when the CBI charged him with conspiracy to sell mobile phone licenses at cut-rate prices to the benefit of a few companies.

The scandal is believed to have cost the Indian government up to $40 billion in lost revenue.