More oversight of grant programs from the U.S. Department of Justice is needed, the agency's inspector general told lawmakers Tuesday.

Michael Horowitz, the DOJ IG, told the House Subcommittee on Crime, Terrorism, Homeland Security and Investigations that more efficient management of grant programs is the top challenge facing the department.

Through its three grant-making offices, Horowitz said the DOJ has awarded roughly $15 billion over the past five years.

During that time, the IG's office has issued more than 200 grant-related audits, containing about 1,000 recommendations and almost $100 million of "dollar-related" findings, such as questioned costs or funds that could be put to better use.

"We need to be able to share information more effectively across agencies and IGs," Horowitz told the panel.

Consolidation of overlapping grant programs will also help save taxpayer money, he said.

In addition, Horowitz told Congress that the government lacks "real-time knowledge regarding recipients' use of grant funds."

View the testimony here.