Washington (CNN) The two aides to Environmental Protection Agency Administrator Scott Pruitt who received substantial raises also each received an earlier pay increase, according to an agency inspector general report released Monday.

The aides are not identified by name in the report, but multiple details, including salary information, correspond with an account first reported by The Atlantic . A former deputy chief of staff to Pruitt later briefed congressional investigators about the raises.

The documents show the two aides' raises were signed off by Pruitt's chief of staff, Ryan Jackson, who in some instances signed his name "Ryan Jackson for Scott Pruitt" on Pruitt's stationary.

Whether the raises were granted with or without Pruitt's knowledge has emerged as a key question, both because of the size of the raises and the White House's previous decision to turn down pay bumps for the aides. One of the two aides wrote in an email to human resources that her raise was approved by the administrator.

Pruitt insisted in a recent interview that he did not know the raises were being granted.

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