(Marlon Correa/The Washington Post) (Marlon Correa/The Washington Post)

Wisconsin Gov. Scott Walker (R) on Sunday described the e-mail controversy involving his administration's use of a secretive e-mail system as “old news.”

“This is about a case that was closed last March," Walker said on "Fox News Sunday," noting that a Democratic district attorney already reviewed the information. "Last year, in March, he announced the end of that case. Plain and simple, it’s old news."

Six people connected to Walker were convicted in the district attorney's investigation, but Walker was never charged. The governor declined to say whether he personally used a secret e-mail system.

“You had a Democratic district attorney spend almost three years looking at almost every single of one those communications, interviewing people, talking to people and closed the case last March.”

Walker described the renewed controversy, which arose with the release last week of more than 20,000 e-mails his time as Milwaukee County executive, as an attempt by Wisconsin Democrats to deflect attention away from the state's budget turnaround from a $3.6 billion deficit to a nearly $1 billion surplus during his tenure as governor.

“They desperately want to switch the subject on a subject that’s already been resolved as of last March,” Walker said.