The State Department’s Inspector General has found classified information sent to the personal email accounts of former Secretary of State Colin Powell and the senior staff of former Secretary of State Condoleezza Rice, NBC News has learned.

In a letter to Undersecretary of State Patrick Kennedy dated Feb. 3, State Department Inspector General Steve Linick said that the State Department has determined that 12 emails examined from State’s archives contained national security information now classified “Secret” or “Confidential.” The letter was read to NBC News.

Two of the messages were sent to Powell’s personal account, and 10 were sent to personal accounts of Rice’s senior aides, the letter said.

None of the messages were marked classified when originally sent, and none were determined to include information from the intelligence community, Linick said in the document.

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Colin Powell told NBC News he strongly disputed that the information in the messages was classified, and characterized the contents as innocuous. Said Powell, “I wish they would release them so that a normal, air-breathing mammal would look at them and say, ‘What’s the issue?’”

Linick said his initial findings suggest there could be a lot more classified material in State’s unclassified archives. He recommended that State take steps to find and remove it.

The IG came upon the material during the course of a review of how current and past secretaries of state deal with classified material and with email. The review was prompted by the current controversy over Democratic presidential candidate Hillary Clinton’s use of a personal computer server to conduct government business while secretary of state.

Linick’s findings will be seen as helpful to Clinton, because they show that past secretaries of state and senior officials used personal accounts to conduct government business and occasionally allowed secrets to spill into the insecure traffic.