A newly disclosed memo shows the US Office of Special Counsel shut down an investigation into the prosecution of former Alabama Governor Don Siegelman last year. Siegelman is currently free on bail while he appeals a conviction on corruption charges. Critics say he is the target of a political witch hunt. More than fifty former state attorney generals have called for a congressional investigation into Siegelman’s case. The new memo shows Special Counsel Scott Bloch ordered investigators to abandon the probe over their objections. Siegelman says Bloch should explain why he shut down the investigation.