CBI on Tuesday briefed Joint Parliamentary Committee about the findings and investigations on the 2G scam. While addressing a news conference in New Delhi, chairman of Joint Parliamentary Committee P C Chacko informed about details of CBI's briefings. Zeroing on the key areas of investigation, Chacko said violation of first-cum-first serve policy, dual technology approval and spectrum allocations, eligibility of companies, non-revision of entry fee are the issues on which CBI is investigating.