The Departamento de Operações de Informações - Centro de Operações de Defesa Interna (English: Department of Information Operations - Center for Internal Defense Operations) was the Brazilian intelligence and repression agency during the military government (1964–1985). This period started on March 31, 1964 with the removal of the civilian government by military forces and ended in the 1984. DOI-CODI was responsible for suppressing internal dissent against the regime. It acted as a political police, using torture and other counter-insurgency methods, with a focus on anti-communism. Several political activists, intellectuals, artists, college students and journalists were interrogated and at times tortured by the DOI-CODI throughout its existence.
The first DOI unit started in São Paulo as a private organization called "OBAN - Bandeirante Operation" (Operação Bandeirante - OBAN). OBAN was an illegal organization created using members of the federal police, civil state polices, military state polices and select members of the armed forces. It was financed by private and corporate entities.
Each state had a DOI unit subordinated to CODI, which had the role of centralizing the operations. The DOI units' composition mirrored that of the previous OBAN.
The largest DOI-CODI, that of São Paulo, had at its peak nearly 250 agents, occupying a large building on Tutóia street. The building gained the infamous nickname of "Tutóia Hilton" (after the Hanoi Hilton of Vietnam) due to the extensive torture which took place in its basement.