In 1973, then-CIA-director Richard Helms ordered all documents relating to MKUltra destroyed. However, 20,000 pages of documents were misfiled and survived the purge. In 1977, Congress organized the Church Committee and examined the records. As a result of the findings, Presidents Ford, Carter, and Reagan issued orders banning all future human experimentation without consent by government agencies, and some remittances were paid to those harmed by the tests.
How illegal was this?
The project violated the Nuremberg codes, agreed to by the United States after the trials of Nazi war criminals, by administering drugs without informed consent. At least two people, Frank Olson and Harold Blauer, died as a result of being drugged without their knowledge. The true extent of psychological damage and death toll is impossible to know, as the records were mostly burned and the unscientific nature of many tests would make it impossible to determine what later events (for example, suicide) were attributable to the tests.