NEW DELHI: The Central Bureau of Investigation has initiated 11 preliminary enquiries against nine Chhattisgarh business groups for allegedly exporting iron ore worth Rs 72 crore meant for consumption in domestic market.

CBI sources said the agency has started these inquiries for alleged duty evasion in the exports of 7.28 lakh metric tonnes of iron ore from Kolkata during 2008-11. Officials say that some customs officials are also under the scanner for conniving with these private companies.

The sources refused to share details of Chhattisgarh based business groups which have been named as it is still the initial stage and disclosure of the names could hamper further investigations.

The sources said rates of iron ore for consumption in domestic market are less because of relaxation in duty whereas for exports these are on higher side.

The agency alleged that these business houses claimed that iron ore was for domestic consumption but allegedly exported it to various countries from Kolkata port in collusion with customs officials.

Earlier as well, CBI has been probing cases of iron ore export in different states including Karnataka and West Bengal.

In 2012, a multi-disciplinary investigation including by CBI into iron ore export had revealed a massive fraud by several mining companies by showing transport of iron ore for exports through railways as movement for domestic consumption.