In the report, issued Tuesday, European human rights investigator Dick Marty says there was evidence the United States was "outsourcing" torture to European countries.
But he said he had no formal evidence for the existence of secret CIA detention centers in Romania or Poland, as alleged by human rights groups.
A spokesman for the U.S. State Department, Sean McCormack, said the European document was simply a collection of old reports wrapped up in new rhetoric.
The U.S. has come under strong criticism for allegedly operating secret detention centers in Europe. U.S. officials have not confirmed or denied the existence of the detention centers, but say that no laws were broken.