From the AP:
Federal prosecutors are conducting a criminal investigation into the levee failures that swamped New Orleans, looking into the possibility of corruption in the design, construction and maintenance of the flood barriers.
U.S. Attorney Jim Letten said Wednesday that his office began the investigation the week after Hurricane Katrina.
"The scope of our interest is very broad," he said.
He said some officials were found to have undisclosed conflicts of interest, and "we're extremely concerned about those." He would not give details.
James Bernazzani, FBI agent in charge in New Orleans, said agents have received numerous tips about possible malfeasance.
Other investigations are being conducted by Louisiana's attorney general, who is looking into whether poor construction or design flaws played a role in the failures, and the New Orleans district attorney, who raised the possibility that faulty materials were used in the floodwalls.