Regional security officer Wayne May, who has been asked to leave India, was the coordination officer of the India-US anti-terrorism assistance programme and a special agent of the Bureau of Diplomatic Security, the division of the US State Department that is also the complainant against Khobragade in the New York case.
New Delhi believes May and his wife, Alicia Muller May, who too is a diplomat and is posted at the US Embassy as a Community Liaison Officer, were central to the entire issue of evacuating domestic help Sangeeta Richards family and the action against Khobragade.
Wayne, who has put in over 27 years of service in the US government and managed the more than 420 security staff and investigative officers at the mission in New Delhi, was the main liaison to Indian police agencies for high profile visits from the US and was the coordinator from the American side to the anti-terrorism assistance programme.
The expulsion, sources said, was ordered as India had reasons to believe the diplomat is closely involved in the processes relating to the case and the subsequent unilateral action by the US.
As an officer of the Bureau of Diplomatic Security, Wayne was also allegedly coordinating with his counterparts in New York who had filed the official complaint of trafficking against Khobragade.
Sources said India had initially thought of taking action against Alicia, a diplomat of the first secretary rank, as she had allegedly used her privileges to buy tax-exempted air tickets for the husband and children of Richard who left on trafficking visas.
This, sources said, was illegal as only diplomats and their families are eligible for the tax exemption.
However, New Delhi subsequently decided that reciprocal action should be taken against a diplomat of the same rank as Khobragade, resulting in the notice to the US to withdraw Wayne, who is a consular level officer.
Wayne, who has served in the Diplomatic Security Bureau since 1988, has worked in Thailand, Colombia, Niger, Singapore and Greece before being posted to India in 2010. He was in charge of the entire security and investigation team in India that included a deputy regional security officer for investigations, four assistant regional security officers, two office management specialists, one residential security coordinator, six foreign service national investigators, 10 marine security guards and 400 local guard personnel.
In an interview to an international publication, Wayne had described that the challenges of his posting in India include unhealthy living conditions like air and water pollution, the threat of disease and sickness, bad traffic and everything else that one would associate with a developing country with a population of over 1.2 billion.
Sources said the last time India expelled a US diplomat was in September 1981 when political counselor George Griffin was asked to leave.