Updated 1:57 p.m. ET
So far, Congress and the media haven't had much luck getting answers on the Bureau of Alcohol, Tobacco and Firearms' ongoing "gunwalking" controversy.
The Department of Justice and ATF have missed repeated deadlines to turn over information and documents to Sen. Charles Grassley (R-Iowa), who's investigating. ATF Acting Director Kenneth Melson (at left) was scheduled to appear before a Senate hearing Thursday, in which he would likely have been asked questions about the scandal. However, CBS News has confirmed Melson has now been pulled from the hearing witness list.
We contacted the Senate Foreign Relations Committee to ask why Melson is no longer scheduled to appear. They referred us to the office of Sen. Robert Menendez (D-N.J.) who chairs the subcommittee holding the hearing. A press spokeswoman at the senator's office said it was Melson's decision not to testify, and that the subcommittee doesn't have jurisdiction over ATF.
Later, a spokesman told us in an email, "The Subcommittee had invited, but not confirmed, Mr. Melson as well as other officials from ATF to testify at the hearing this week. In the end, ATF declined to send a representative."
The gunwalking investigation may also have derailed any chance for Andrew Traver, President Obama's nominee to be the permanent head of the ATF, to have confirmation hearings anytime soon. Mr. Obama made Melson, a former Justice Department attorney, acting director in April 2009. Sources on the Senate Judiciary Committee believed confirmation hearings for Traver were about to be scheduled before the gunwalking scandal broke. Now, they believe confirmation hearings for Traver will not happen in the near future.
Correction: A former version of this post incorrectly stated that the confirmation hearings would be for Melson instead of Traver.
All of Investigative Correspondent Sharyl Attkisson's reports, videos and articles can be found in one place at cbsnews.com/sharylattkisson.