Rajesh Sahni, an Additional Superintendent of Police rank official, shot himself on his temple at 12.45 pm in his office, ADG (Law and Order) Anand Kumar said, according to PTI.
Sahni, a 1992-batch Provincial Police Services (PPS) officer, used his own service revolver to end his life.
It was not immediately clear as to why Sahni took the extreme step and the UP police was trying to ascertain the reasons behind the alleged suicide.
This was not the first time when a top ATS officer took the extreme step to end life. Earlier on May 11, former chief of the Maharashtra Anti-Terrorism Squad, Himanshu Roy had committed suicide.
Roy, who was serving as the Additional Director General of Police in Maharashtra, shot himself with his service revolver at his residence in south Mumbai. He left a suicide note and cited "extreme depression" reason behind committing suicide.
(With inputs from agencies)