Mitch McConnell investigation assisted by U.S. Capitol Police

FRANKFORT, Ky. (AP) - U.S. Capitol Police are assisting the FBI in a probe into the secret taping of a private campaign strategy meeting involving Senate Republican Leader Mitch McConnell and several of his aides.

Capitol Police officers assigned to provide security for McConnell were at the meeting in Louisville in February.

Capitol Police spokesman Shennell Antrobus acknowledged that his agency is assisting the FBI with the investigation. He declined additional comment, saying his agency doesn't discuss security measures for federal lawmakers.

Progress Kentucky, a liberal political fundraising group, has been tied to the recording that was leaked to Mother Jones magazine and published last week. Mother Jones said the recording came from a confidential source. It posted audio and a transcript of the meeting online.