Attygalle joined the
police force on 1 October 1928 as a
Sub-Inspector of Police. In October 1947 he was promoted to
Assistant Superintendent of Police (ASP) as ASP Crimes, Colombo (South) and thereafter was appointed ASP, CID in November 1948; ASP, Ambalangoda January 1950; June 1951 ASP, Colombo Crimes; April 1953 ASP, Western Province (North) and in January 1951 ASP, Jaffna. In January 1962 Attygalle, who was then the
Superintendent of Police of the
Criminal Investigation Department (CID), played a major role in stopping the
attempted military coup. Attygalle together with
Felix Dias Bandaranaike and
S. A. Dissanayake (Deputy Inspector General of the CID) informed
Prime Minister Sirimavo Bandaranaike at her residence about the attempt to take over the Government by a coup by certain army, navy and police personnel, on the eve of the coup, which resulted in its failure to occur and the arrest of the coup organisers. In 1963 following the appointment of Dissanayake as Inspector-General of Police he took on the role of Deputy Inspector General of the CID. In early 1966 Dissanayake was placed on compulsory leave, he was then replaced by Attygalle as Inspector-General in June that year. In July 1966 he arrested
Major General Richard Udugama, the
Commander of the Ceylon Army, at the
Bandaranaike International Airport for his purported involvement in an
alleged coup d'état attempt. Udugama was subsequently found not guilty by the
Supreme Court and acquitted of all charges. On 1 October 1966 Attygalle established the Police Public Relations Division at Police Headquarters, Colombo. On 1 April 1967, Attygalle arranged for the Police Training School to be shifted from
Kalutara to Echen Square Barracks, which were occupied by the
Sinha Regiment of the
Ceylon Army. The Police Training School was subsequently relocated back to its original premises in Kalutara in December 1970. On 8 July 1967 he retired from his position as Inspector-General of Police. ==Later work==