'Coalgate controversy': India police raid coal firms
4 September 2012 Last updated at 11:16 BST
Police in India are carrying out raids across 10 cities as part of an investigation into alleged corruption in the allocation of coalfields.
Police say they are searching the premises of five companies, which allegedly misrepresented facts prior to being allocated the coalfields.
Government officials and company employees are also under investigation.
State auditors recently said India lost $33bn (£20bn) selling off coalfields too cheaply.
Sanjoy Majumdar reports from New Delhi.