Wisconsin Gov. Scott Walker (R) has spoken publicly on the apparent investigation of former aides from his time as Milwaukee County Executive -- saying that he does not know any of the details.
"We don't know what exactly is involved," Walker told the Associated Press
on Friday, when asked at an unrelated event in Milwaukee.
He also added: "Until we know, obviously it's a concern but again, I don't know any more details than what I've seen reported in the media outlets around the state."
The "John Doe" investigation
-- a secret proceeding in which witnesses can be subpoenaed to testify under oath, but are forbidden from talking publicly about the case -- is reported to have originally stemmed from a staffer resigning in 2010, when she was found using her county time to post reader comments on online newspaper article promoting Walker's gubernatorial candidacy and criticizing his opponents.