An internal CIA panel concluded in a report released Wednesday that agency employees should not be punished for their roles in secretly searching computers used by Senate investigators, a move that was denounced by lawmakers last year as an assault on congressional oversight and a potential breach of the Constitution.

Rejecting the findings of previous inquiries into the matter, the CIA review group found that the agency employees' actions were "reasonable in light of their responsibilities to manage an unprecedented computer system" set up for Senate aides involved in a multiyear probe of the CIA's treatment of terrorism suspects.

The agency panel, which was led by former U.S. senator Evan Bayh (D-Ind.), cited a lack of clear ground rules between the CIA and the Senate, and it faulted CIA workers for missteps including reading e-mails of congressional investigators.

But while such transgressions were "clearly inappropriate," Bayh said in a statement released by the CIA, they "did not reflect malfeasance, bad faith, or the intention to gain improper access" to sensitive Senate material.