On Tuesday the regulators ruled an in-depth investigation was needed as they believed there was "no obvious market failure" that needed to be addressed.
Since then, 50 attorneys generals have launched a an in-depth investigation into the way BofA and other lenders like Wells Fargo and JPMorgan Chase handled foreclosures.
But Mr Thomas said the initial investigation had "identified a number of questions and concerns which I now consider warrant further in-depth audit investigation".
He said a five-strong panel of party figures - including at least three women - would be assembled to conduct a "thorough and in-depth" investigation into the allegations.
He said a five-strong panel of party figures - including at least three women - would be assembled to conduct a "thorough and in-depth" investigation into the allegations levelled against Lord Rennard.
This law has now been in place for about five years, but a federal investigation last July, in addition to the in-depth study from the Mayors Against Illegal Guns, found the vast majority of states fail to pass on mental health records to the federal system.