Yi Hong-muk (1895–1960) was adopted as the son of Viscount Yi Byeong-mu and inherited his viscount title in March 1927. A graduate of the Industrial Technical School (1918), he was active in pro-Japanese organizations such as the Dongyohoe, the Korea Confucian Federation, and the Korea Wartime Patriotic Corps between 1937 and 1941. After liberation he was arrested in 1949 by the Special Committee for Anti-National Activities Investigation, and is listed as a pro-Japanese collaborator by the government and the Dictionary of Pro-Japanese Biography.