(CNN) -- U.S. Attorney General Eric Holder will head to the Gulf Coast Tuesday to survey the BP oil spill and meet with state attorneys general and federal prosecutors from Louisiana, Alabama and Mississippi, according to the Justice Department.
Last month a group of senators -- including Environment and Public Works Committee Chair Sen. Barbara Boxer, D-California -- sent Holder a letter expressing concerns "about the truthfulness and accuracy of statements submitted by BP to the government in its initial exploration plan for the site," and asking Holder to investigate possible criminal and civil wrongdoing.
But in a reply to that letter last week, a Justice Department official did not say whether a criminal investigation had begun.
"The Department of Justice will take all necessary and appropriate steps to ensure that those responsible for this tragic series of events are held fully accountable," Assistant Attorney General Ronald Welch wrote.
Holder said last month that the Justice Department would "ensure that BP is held liable."