A Democratic super PAC whose members have been under investigation for surreptitiously recording a meeting held by staff of Senate Minority Leader Mitch McConnell (R-Ky.) is shutting down.

Mitch McConnell (Alex Brandon/Associated Press) Mitch McConnell (Alex Brandon/Associated Press)

Progress Kentucky made big headlines with its tactics -- including the recording operation and making an issue of the heritage of McConnell's wife -- but it never raised much money, and the Federal Election Commission on Friday approved its termination as a super PAC.

The group, founded to help defeat McConnell in 2014, recently filed mid-year campaign finance report showed it raised less than $15,000 over the first six months of the year -- a meager amount in a race that could well be the most expensive Senate contest ever.

One of the men responsible for the recording, Curtis Morrison, said in May that a grand jury was investigating the matter. No charges have been filed yet.

The shuttering of the super PAC is not surprising. Its Twitter account hasn't been active since the recording story broke in mid-April, though Morrison remains outspoken and active on his personal account.