Military intelligence
From 1990, he was attached to the Military Intelligence Unit of the Joint Operations Command which later became the Directorate of Military Intelligence and he was transferred to the Military Intelligence Corps with its formation in 1990. He was promoted to the rank of captain on July 2, 1992, and afterwards to major on July 2, 1995. During this time he had served as general staff officer III (Intelligence) at Army Headquarters; officer commanding, Military intelligence training section; group commander, Intelligence Security Group in Jaffna for about three and a half years, group commander at the Directorate of Military Intelligence in Colombo for about three years since 1997 and general staff officer I (intelligence) in Vavuniya from 2000 to 2001. He under went several foreign training courses, such as the he Intelligence Staff Course and Counter Intelligence Course at the Directorate General of Forces Intelligence; the Junior Command Course at the Army War College, Mhow; South Asian Peace Keeping Course in Hawaii and the International Intelligence course in the USA. He was appointed commanding officer, 1 Military Intelligence Corps in November 2004. At the time of death he was also head of the Colombo Cell. Muthaliff had provided vital intelligence for major military operations such as Operation Balavegaya, Operation Jayasikurui and provided Brigadier Janaka Perera with critical information forewarning him of the LTTE attack on Weli Oya. The LTTE had attempted to assassinate Muthaliff in two previous occasions, with gunmen in Vavuniya and with a suicide bomber in Jaffna.