New Delhi: Former Union government secretary E.A.S. Sarma has written to Revenue Secretary Arvind Shrivastava urging the Enforcement Directorate (ED) and the Central Board of Direct Taxes (CBDT) to investigate whether the Rashtriya Swayamsevak Sangh (RSS) engaged a US lobbying firm by paying $330,000, and whether such funds should attract tax scrutiny in India. His letter, reported by The Wire, raises serious questions about the source, legality and disclosure of funds allegedly used by the RSS for lobbying in the United States.