EPA chief Scott Pruitt appeared to change his story regarding steep pay raises given to two of his top staffers.

During an interview on April 4, Pruitt said he did not know about the raises at all.

But during his congressional testimony on Thursday, Pruitt refused to say whether or not he knew about the raises, instead saying he was not aware of the amount the salaries were raised by or that the White House had refused to approve them.

Environmental Protection Agency chief Scott Pruitt appeared to change his story regarding steep pay raises given to two of his top staffers, which he originally said he knew nothing about, during congressional testimony on Thursday.

Rep. Paul Tonko, a New York Democrat, questioned on Pruitt on his knowledge of the raises, which were given to two aides Pruitt brought to Washington from Oklahoma.

"I was not aware of the amount, nor was I aware of the bypassing or the [White House Office of Presidential Personnel] process not being respected," Pruitt said.

Pressed by the congressman, Pruitt refused to say whether he knew about the raises at the time.

The EPA chief said that he "delegated" authority to his chief of staff, Ryan Jackson, who signed off on the hefty raises.

But in an interview with Fox News on April 4, Pruitt told a different story.

The administrator repeatedly claimed in the Fox interview that he did not know about the pay raises, or who signed off on them, before they were made or at the time they were made. He said he only found out about them the day before that interview, April 3.

"I did not know about the pay raise. I did not approve the process," Pruitt told Fox, adding that he had reversed the decisions and that the raises "should not have happened."

Sarah Greenwalt, Pruitt's 30-year-old senior counsel, received a raise of over $66,000, bringing her salary to $164,200. And Millan Hupp, Pruitt's 26-year-old scheduling director, had her pay bumped from $86,460 to $114,590.

After the White House reportedly refused to sign off on the proposed pay hikes for Greenwalt and Hupp, the EPA used a backdoor provision through the Safe Drinking Water Act, which allows the administrator to hire up to 30 employees without White House or congressional approval in areas of critical need, to approve the raises.

According to internal emails reported on by The Atlantic on April 9, Greenwalt insisted that Pruitt approved her raise.

Greenwalt "definitively stated that Pruitt approves and was supportive of her getting a raise," an administration official who has seen the emails told The Atlantic.

A second administration official told The Atlantic that the email "essentially says, 'The administrator said that I should get this raise.'"

Jackson took the fall for the controversial decision.

In an April 9 statement, Jackson said Pruitt was not aware of the amount the staffers' salaries were being raised by, nor was he aware of the process through which they were implemented. But Jackson did not say that Pruitt was unaware that the raises were being given.

"Administrator Pruitt had zero knowledge of the amount of the raises, nor the process by which they transpired," Jackson said in his statement. "These kind of personnel actions are handled by myself, EPA's HR officials and PPO."

But if Pruitt was in fact unaware of the raises, he may have violated the law, as the administrator is required to approve all hiring and salary changes under the Safe Drinking Water Act.