In 1913, Kotewall was named Clerk to the Magistracy and JP. By 1919, he was in trade as the manager of the Hong Kong Mercantile Company. In 1923, he was invited to join the
Legislative Council as an unofficial member, a position he held until 1935. In 1936, he joined the
Executive Council. During the Japanese occupation of Hong Kong, Kotewall served as the chairman of the Japanese military government's Chinese Representative Council and assisted the Japanese Army in governing Hong Kong. After Sir Mark Young was restored as the governor of Hong Kong, Kotewall submitted a 66-page report explaining the causes and consequences of his actions as a Chinese representative during the Japanese occupation period, but it was not accepted by the British government. Although he was not prosecuted for treason, he was still blacklisted by the Hong Kong government and for the rest of his life would never again be appointed to official positions. At the same time, he was also listed as one of the traitors sought by the Guangdong government of the Republic of China, so he rarely subsequently participated in public life. Kotewall died in 1949. He was decorated the insignia C.M.G by
King George V in 1927. == Personal life ==