Sunlight Foundation reports that the most likely candidate for the senator who placed a secret hold last week on a transparency bill is Sen. Jon Kyl, R-AZ. Kyl staffers seem to be rather evasive in answering inquiries about their boss and the hold.

But two other GOP senators remain in contention, according to Sunlight, including Sen. David Vitter of Louisiana and Sen. Judd Gregg of New Hampshire.