The article gives examples of obtaining new information about martyrs in the 20th century, namely the clergymen and parishioners of the Vysokopetrovsky Monastery in Moscow, including its abbot Archbishop Bartholomew (Remov). The new data are obtained by researching the newly discovered documents in private and foreign archives, a more thorough critical and comparative analysis of the already well-known sources, and interviewing individuals who personally knew those people, who were repressed and lived up to the second half of the twentieth century. The sources introduced into the scientifi c activities come from the private archive of his-torian Sergey Belyaev, as well as from the archives of the General Curia of the Assumptionist Congregation in Rome (the letters from Bishop Pie Eugene Neveu, apostolic administrator in Moscow in 1926-1936) and the Historic archives of the Secretariat of State. There are subjected to critical examination the investigative materials against Archbishop Bar-tholomew (Remov) and the members of the community, who in the investigation case were named members of the “Catholic group of the counter-revolutionary organization under the illegal “Petrovsky monastery”. The author refutes the conclusions made earlier by the researchers on the existence of a Catholic group in the Vysokopetrovsky Monastery, as well as casts doubt on the hypothesis on the adherence of the monastery abbot Archbishop Bartholomew (Remov) to Catholicism.