What is ÚZSI?

The ghost of Milan Chovanec is now at the center of Czech politics. ČSSD called off government talks on Thur. because it didn't get back the interior ministry that Chovanec had been running, and just before this happened three leading investigative reporters joined together to accuse the police and GIBS internal-affairs unit of a coordinated effort to intimidate them. Chovanec's name wasn't mentioned in their joint statement, nor did it come up last night when the three appeared together on Czech TV. Andrej Babiš is instead assumed to be the guilty party. Babiš, in turn, accuses Chovanec of having used the ÚZSI foreign-intelligence service to leak the information in question to journalists. ÚZSI is the Czech equivalent of the CIA and is limited in its ability to conduct operations on Czech soil. The issue is two-fold and comes down to this: Did Chovanec use the interior ministry and ÚZSI to commit criminal acts, and is Babiš breaking the law by trying to prove it?