They have gone over 20 years since its secret files KGB leaked from Russia. The files are in the thousands and, according to the FBI, include "the most complete and extensive espionage archive we have ever had from any source." The documents include information from the KGB about secret Russian weapons, cryptocurrencies, Russian spies, and information about the activities of Pope John Paul II. They are known as the Mitrokhin Archives, and are now available in its Archive Churchill College.
The records leaked by Vasiliy Mitrokhin, who was working on a KGB information file between 1972 and 1984. During his stay there, Mitrokhin is said to have had free access to hundreds of thousands of confidential records. Eventually, when he came into conflict with the Soviet government, he began copying the documents and smuggling them into his shoes and pocket jackets. Mitrokhin then hid the records that remained hidden until he revealed them to the United Kingdom in the 90 decade.
But today you can find online.