Former Environmental Protection Agency official John Beale is in prison for defrauding the government of almost $900,000 by pretending to be a CIA spy, and now congressional investigators are turning their attention to a colleague suspected of helping him.

Robert Brenner, Beale's best friend at EPA, has refused to cooperate with an inspector general's investigation, and Sen. David Vitter, R-La., and House Oversight and Government Reform Committee chairman Darrell Issa, R-Calif., want answers.

"[I]t appears Beale could not have accomplished his crimes without Brenner's assistance,” Vitter and Issa wrote to Brenner's attorney, Justin Shur, in a Monday letter.

The Republicans suggested that Brenner has already lied to Congress, in addition to lying to the EPA about in recommending Beale for bonuses, and recommending him for a lucrative promotion.

"In each of these instances, your client’s actions facilitated Beale’s fraud," Issa and Vitter wrote. "Moreover, we have learned that your client often corroborated Beale’s lies.”

The investigators told Shur they want all of Brenner's documents pertaining to Beale by April 23.

In a separate letter, they also asked EPA Administrator Gina McCarthy to hand over all of Brenner's documents from the time he hired Beale in 1987 to the time he retired in 2011.