( CNN ) -- U.S. Attorney General Eric Holder said Tuesday the Justice Department has launched a criminal investigation into the massive oil spill spreading through the Gulf of Mexico . Holder said the investigation , which began `` some weeks ago , '' would be comprehensive and aggressive . He promised that the federal officials will prosecute anyone who broke the law . `` We have begun both a criminal as well as a civil investigation as is our obligation under the law , '' Holder said . `` We have what we think is a sufficient case to have begun a criminal investigation . '' Holder emphasized that the investigation will cover all aspects of the oil spill , including the deaths of 11 workers in the April 20 explosion and fire on the Deepwater Horizon rig that started the leak . He refused to name any potential targets of the investigation , saying , `` I do n't want to unnecessarily cast aspersions . '' However , Holder said `` nothing is off the table '' in the probe , and he cited false statements as one of several potential targets of criminal charges . `` This disaster is nothing less than a tragedy , '' Holder said . `` As our review expands in the days ahead , we will be meticulous , we will be comprehensive , and we will be aggressive . We will not rest until justice is done . '' Holder stressed that `` anyone found responsible for this spill ( must be ) held accountable . That means enforcing the appropriate civil -- and if warranted , criminal -- authorities to the full extent of the law . '' Among other things , Holder said Justice Department lawyers are examining possible violations of the Clean Water Act and the Oil Pollution Act of 1990 . He also said prosecutors are looking into potential violations of the Migratory Bird Treaty and Endangered Species Acts , which provide penalties for injury and death to wildlife . BP responded in a statement that it `` will cooperate with any inquiry the Department of Justice will undertake , just as we are doing in response to the other inquires that are already ongoing . '' Holder made the announcement during a visit to the Gulf 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 . '' They asked the attorney general to investigate possible criminal and civil wrongdoing . In a reply to that letter last week , a Justice Department official refused to 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 the Justice Department would `` ensure that BP is held liable . '' Boxer issued a statement Monday praising the criminal probe . `` In preparation for the Environment Committee 's hearings on the oil spill , it became clear that BP 's assurances that they could respond effectively to a serious spill at this site were totally at odds with reality , '' Boxer said in the statement . `` What is happening in the Gulf -- eleven people dead , and an entire ecosystem and the jobs that depend on it at risk -- justifies a thorough criminal investigation . '' CNN 's Scott Bronstein and Aaron Cooper contributed to this report .
NEW : Attorney General Eric Holder says enough evidence existed to start a criminal investigation . NEW : Senator lauds criminal investigation launched by Department of Justice . DOJ looking into potential violations of Clean Water Act , Oil Pollution Act of 1990 and other laws . Holder visits Gulf Coast on Tuesday to survey BP oil spill .