EPA official scrutinized over emails to resign A top EPA official plans to resign, just three weeks after Republican Sen. David Vitter questioned him over the use of a personal email account to conduct "official business." EPA spokeswoman Alisha Johnson confirmed to FoxNews.com that Region 8 Administrator James Martin plans to resign effective Friday. She said it was "for personal reasons." Martin was facing questions about his use of personal email, as former EPA boss Lisa Jackson also comes under scrutiny for using alias emails to communicate with employees. The agency reportedly is disputing the notion that Martin's resignation had anything to do with the email controversy. But Vitter, R-La., top Republican on the Senate environment committee, claimed Martin is leaving at least in part because of the "open investigation about his use of a non-official email account to conduct official business." Vitter claimed Martin had recently hired legal counsel, following a Jan. 29 letter in which Vitter and Rep. Darrell Issa, R-Calif., challenged the EPA official. Vitter and Issa said documents showed he used his private me.com account to confirm a meeting with the general counsel for the Environmental Defense Fund. The EPA, according to Politico.com, downplayed the communication as a one-time occurrence. But the Republican lawmakers wrote that "it does not appear that this transaction was an isolated incident." "Rather, the body of emails suggests that you regularly used this personal email account to stay informed on matters relating to your official duties," they wrote. Further, they said the issue raises concern that he could be trying to "insulate" himself from formal records requests and "circumvent" federal records law. It's not the first time administration critics have tried to tie a high-profile resignation to the unfolding email controversy. A Washington attorney suing the Obama administration for access to Jackson's alias emails claimed in December that a decision by the Justice Department to release thousands of those emails contributed to Jackson's decision to resign. Chris Horner, a senior fellow at the Competitive Enterprise Institute, said the scrutiny over the alias emails is clearly a factor. Jackson, though, said she was leaving after four years for "new challenges, time with my family and new opportunities to make a difference." Several top officials in the Obama administration have resigned in recent weeks, as part of what the administration says in normal turnover going into a second term. Vitter, in a statement Tuesday, turned his scrutiny to Jackson's acting replacement Bob Perciasepe. He noted that another tranche of emails released late last week showed Perciasepe using a personal account. The emails -- which included a number involving Jackson's alias "Richard Windsor" account -- largely showed routine chatter about press clippings. CEI later complained that the documents were heavily redacted. But Vitter objected to the use of personal accounts. Now we know that Lisa Jackson's acting replacement, Bob Perciasepe, appears to have been doing the same thing to dodge the agency's mandatory recordkeeping policy. EPA owes us all some answers about their absolute disregard for transparency, especially from their acting administrator or any potential nominee to be administrator," Vitter said. The EPA has downplayed Republican concerns. In November, when reports of the alias accounts were first surfacing, an EPA spokesman said the agency has for roughly a decade assigned internal and public email addresses to administrators -- and that they use the internal ones to communicate with staff because of the massive amount of traffic on the public accounts.