NEW DELHI: The dramatic events that began unfolding Thursday evening had their origin in a meeting that National Security Advisor AK Doval held with Cabinet ministers heading sensitive portfolios last December. His cautioning of ministers against leakage of sensitive documents and classified information affecting national security itself was a follow up of his letter dated October 13, 2014, on the same issue to Cabinet Secretary Ajit Seth However, the government was left red-faced when the letter to Seth itself got leaked and its contents appeared in a prominent New Delhi-based newspaper.Sources among investigators said a plan to stem the leaks was set in motion somewhere after the December meeting. CCTV cameras were installed in petroleum ministry — the most favourite haunts of touts and lobbyists — soon after. The process of installing CCTV cameras was on in other ministries too, including coal MHA and defence.However, the latest events showed that even CCTV cameras were disabled to a good extent. The sources told ET that this was just the beginning of the probe and it was likely to go up to senior level to include some bureaucrats of the rank of joint secretary.“The kind of information and documents that the middlemen had access to could not have been obtained without the involvement of senior bureaucrats of the ministry,” claimed one senior police officer, adding that there were explicit directions from the government to get down to the bottom of the whole thing and fix responsibility. So far only junior employees of business houses had been arrested but sources said that there was a “strong possibility” of some senior executives being summoned for questioning in the next few days.“Things are developing fast and the evidence that is coming out is stunning,” the police officer explained. In his December meeting, Doval had warned the ministers about the nexus between the journalists, corporate middlemen and government officials.They were also asked to crack down on the middlemen roaming in these ministries as PROs of big corporate houses or representatives of dubious media publications.