The CBI has begun probing alleged irregularities in the country's first-ever attempt to explore untapped mineral wealth worth thousands of crores lying in the deep sea bed, sensing another mega scam. AIR correspondent reports, a preliminary enquiry has been registered by the agency in connection with the alleged favours extended to the companies by the unknown officials of the Indian Bureau of Mines while awarding licences for exploring minerals in the sea bed of Bay of Bengal and Arabian Sea.