In the year of the 100th anniversary of the World War I (1914-1918) It is important to remember not only the battles and their heroes, but also prisoners of war. The purpose of the article is to highlight the Academia representatives'role in finding of German prisoners of war in the Russian Empire. The problem was solved using the documents from the Academician Mikhail Alexandrovich Rykachev's manuscript collection (St. Petersburg Branch of the Archive of the RAS), introduced into scientific circulation for the first time. During his career academician M. A. Rykachev (1840/1841-1919) had extensive contacts with foreign scientists, he participated in more than 20 international scientific forums, held in England, Austria-Hungary, Belgium, Denmark, Germany, Russia and France, was a member of several international committees and headed some of them. After the World War I, relatives of many scientists from European countries were captured in Russia. Some scholars appealed for help in their quest to M.A. Rykachev. He concerned such requests with understanding, although his eldest son was killed on the German front in November 1914. In December 1914-March 1915 M. A. Rykachev was engaged in Lieutenant Erhard Mazelle and vice-officer Aloys Bock searching. For this, he personally intervened repeatedly to the Central Informational Bureau for prisoners the Russian Red Cross Main Department. Both prisoners were found. Thus, during the World War I, Academician M. A. Rykachev repeatedly helped foreign fellow scientists in search of their relatives or loved ones who were captured on the Russian-German front. Such selfless Russian scientist's activities were one of his international enterprises although did not have any direct relationship to "pure science".