Petrie worked in the
Indian Imperial Police from 1900 serving in a variety of police intelligence roles. He headed the Delhi Intelligence Bureau of the Indian Police and served as the Chairman of the Indian Public Service Commission until 1936. After the outbreak for the
World War II he joined the
Army Intelligence Corps. His highest level in
British India was to chair the
Union Public Service Commission. In April 1941, he was appointed Director General of
MI5. His task was to reorganise the service so that it could improve its efficiency. In the spring of 1946, Petrie retired. He was awarded
Order of the Yugoslav Crown and other decorations. == References ==