While there is an ongoing investigation about data-sharing within the Homeland Security's U.S. Citizenship and Immigration Services, U.S. Sen. Charles Grassley, R-Iowa, wrote Chertoff asking for a "detailed explanation" of where the roadblocks were and who was causing them, The Washington Times reported Monday.
"It will be impossible to address information-sharing problems if government officials avoid talking about them merely to avoid the tough questions," Grassley wrote.
The central point in the information-sharing -- or withholding -- is the Interagency Border Inspection System database available in part by all law-enforcement agencies to search for foreign terror suspects or criminals as well as immigration officials.
The database gets about 35 million background queries per year, the newspaper said.
There was no immediate response from Chertoff's office about Grassley's letter, the Times said.