The Katpol, an abbreviation for Katonapolitikai Osztály (Military Political Department in Hungarian), and it was the main security agency of the Ministry of Defence in Hungary from January 1945 until its break-up in 1950.
Before the Paris Peace Treaty, under the circumstances of the era, when the Hungarian Army was not allowed to plan or act independently, the counterintelligence activities became the most important part of the military, as they meant an easy way to influence the composition of the future officer corps.
For example they undertook an unlawful surveillance of Béla Zsedényi, the Speaker of the Interim National Assembly without a warrant[4] and they also collected data about János Vörös, the Defence Minister.
In August 1948, agents of the Katpol tried to assassinate the Defence Minister Péter Veres, who was the President of the Peasant Party and was one of the most popular politicians of the time in Hungary.
In December 1949 after the communist takeover of the country was finished and all security agencies of Hungary were unified by the decision of the leadership of the Hungarian Working People's Party, the Katpol was incorporated into the State Protection Authority.