Until 1984, the Sri Lanka Police were responsible for internal intelligence functions, first under the Special Branch, and later under the Intelligence Services Division. The perceived failure of the Intelligence Services Division during the riots of July 1983 led the J.R. Jayawardene Government to re-evaluate the nation's intelligence network, and in 1984 the President set up a National Intelligence Bureau. The new organization combined intelligence units from the Army, Navy, Air force, and Police. It was renamed the State Intelligence Service in 2006.
LTTE agents successfully infiltrated Sri Lankan government and military organizations resulting in the Assassinations of several high-ranking Military personnel like Major Tuan Mutalif and Colonel Tuan Meedin both of the Directorate of Military Intelligence putting Sri Lankan Intelligence services in a desperate condition. Under the Defence Secretary Gotabhaya Rajapaksa the intelligence agencies that were in desperate condition built-up a cohesive apparatus, which achieved significant success, including anti-LTTE operations overseas and the SIS played huge role in the Fourth Ealam war.