They've got muck; we've got rakes. TPM Muckraker
The OCE requested extremely detailed information on each lawmaker. According to The Hill:
The OCE wants the dates, times, locations, guest lists, programs and all files, correspondence, notes, e-mails, or "any other documents" regarding fundraising events attended by employees who gave to the legislators during fundraising events from Jan. 1, 2009 to "the present time."
The ethics office requests all documents between the lobbyists and staff of the members, encompassing their district office, congressional, or leadership political action committee aides. It specifically seeks instances of all files regarding the soliciting, encouraging, collecting and facilitating of campaign contributions to the members.
Two of the lawmakers, Hensarling and Price, said the investigation was related to the House financial reform bill. Both Hensarling and Price voted against the bill, and both denied to The Hill that they were influenced by campaign contributions to do so.
The probe is a "preliminary investigation." As The Hill points out, the OCE opened 48 such investigations last year, and only half moved on to the next step.