A former Environmental Protection Agency administrator frequently used a private email account to conduct official business, contrary to previous claims by the agency and court affidavits.

Emails released in Freedom of Information Act (FOIA) litigation between the EPA and the Competitive Enterprise Institute, a conservative think-tank, reveal former Region 8 administrator James Martin often used his personal email account to communicate with the Environmental Defense Fund.

Martin emailed back and forth often between EDF general counsel Vickie Patton to trade contacts, advice, and news as well as to set up meetings.

Martin resigned in February while under congressional investigation for using his personal email address to conduct official business.

The latest release shows the EPA falsely claimed Martin did not use his private email account for official business, one U.S. senator said Friday.

"EPA should start owning up to the facts piling up before them," Sen. David Vitter (R., La.) said in a statement. "Their blatant disregard for proper procedure and transparency is now being regularly exposed, and EPA's leadership must be held accountable."

Court documents first revealed an email between Martin and the general counsel of the Environmental Defense Fund in January. Martin was a lawyer at the EDF prior to joining the EPA.

Vitter and House Oversight and Government Reform chairman Darrell Issa (R., Calif.) sent a letter in January to Martin after the first private email was revealed.

"We are concerned that your use of the me.com email account may be an attempt to circumvent the Federal Records Act, the Freedom of Information Act, and Congressional oversight," the lawmakers wrote.

The EPA denied any wrongdoing took place and said the agency "and the regional administrator have gone beyond any legal requirements in our efforts to ensure full transparency."

"As detailed in public filings, the regional administrator does not use his personal email account to conduct official business," an EPA spokesperson wrote at the time. "That Mr. Martin responded to one email sent to his personal email account to confirm a meeting that appears on his official government calendar does not alter that fact."

Martin declared in a January court filing that "although I do not use private email accounts to conduct EPA business, I did, in fact, search my personal email account for communications that contained the search terms outlined in the FOIA request."

However, Martin frequently communicated with Patton via his personal email account, 14 pages of additional emails produced in ongoing FOIA litigation between the Competitive Enterprise Institute and EPA reveal.

Martin advised Patton on where to hold public forums to discuss the Obama administration’s upcoming new standards for pollution controls in one email.

Patton introduced Martin to Robert Hallman, an adviser to New York Governor Andrew Cuomo whom she described as "Gov. Cuomo's #1 on energy/envt," in another email.

Hallman was chairman of the New York League of Conservation Voters prior to joining the Cuomo administration. Incidentally, Patton also used Hallman’s private Gmail account to introduce the two.

One email chain sent from Martin’s personal account was received by EPA’s deputy chief of staff, a fact Vitter said raises expectations that the EPA had knowledge of the email practice.

Martin pleaded with Patton to use his official work email in another instance.

"Vickie—great news. But please, please, please use my work email address for any communications even remotely related to my work," he wrote in one June 2012 email, one month after CEI first put in a FOIA request for communications between Martin and Patton.

The original search of Martin’s personal account was performed by himself and only included emails stored in his Apple iCloud account. The Competitive Enterprise Institute pressed the agency throughout January in court to fully search Martin’s private email account.

Time stamps on the recently released emails show Martin began forwarding them from his private account to his work account on February 1.

Martin resigned on Feb. 22. An EPA spokeswoman said he resigned for "personal reasons."

Martin’s actions were at odds with multiple executive branch and agency directives.

"EPA has a clear and consistent policy framework against the use of nongovernmental email systems for official EPA business," the agency wrote to the Government Accountability Office in 2008.

EPA political appointees were instructed by the Obama administration in 2009 to "not use any outside email account to conduct official agency business."

The EPA also sent an agency-wide email reminding employees the "EPA prohibits the use of non-EPA email systems when conducting agency business."

Martin is one of several EPA officials to come under the crosshairs of watchdog groups and congressional oversight for alleged transparency lapses.

Former EPA administrator Lisa Jackson, who announced she was resigning in December, used a secret, secondary email account under the name "Richard Windsor" to communicate with other high-level agency officials.

The EPA did not immediately respond to requests for comment.