The Enforcement Directorate has slapped various charges of Foreign Exchange Management Act (FEMA) violations against top telecom firms allegedly involved in the 2G spectrum scam. The firms include Swan Telecom, Loop Mobile, Loop Telecom and S-Tel and the violations amounted to the tune of over 4,300 crore rupees. The Directorate in its complaint filed before the Competent Adjudicating Authority for FEMA violations, said, it is also probing suspected contravention of forex rules in Virgin Mobile, a joint venture of the Tata group. It has charged Shahid Balwa-promoted Swan Telecom, with committing FEMA contraventions to the tune of 3,608 crore rupees. The Directorate said the violation was done by the company in issuing shares to foreign investors at an abnormal value to avoid taking permission from the Foreign Investment Promotion Board.