While the McCaskill and Johnson investigation proceeded, Edwards' office also was conducting an investigation of Alejandro Mayorkas, who at the time was director of U.S. Citizenship and Immigration Services and has since been appointed deputy secretary for DHS.
The subcommittee repeatedly criticized Edwards for his "frequent communications and personal relationships" with senior Homeland Security officials, including Sandweg and former chief of staff Noah Kroloff, as he conducted investigations and audits.
In at least one email, Edwards told Kroloff how much he valued his friendship and that his "support, guidance and friendship helped me be successful this year."
The former Justice Department's inspector general, Fine, said: "It's probably not best to be socializing on a regular basis" with department officials.
"You are part of the department, but independent from the department, and you should conduct yourself in that fashion in all respects," Fine said.
Obama nominated a permanent Inspector General, John Roth, last year. He was approved by the Senate earlier year and took office on March 10.
Edwards was also criticized for seeking legal advice from Homeland Security general counsel's office, despite being required by law to only get such advice from his own counsel or that of another Inspector General, the report said. Edwards told investigators for the subcommittee that he didn't trust his own lawyer or anyone else in that legal counsel's office.
In a written statement, Sandweg said Thursday that the Homeland Security general counsel has long worked closely with the inspector general "on cross-cutting legal and policy issues and to ensure the accuracy of IG audits and reports by reviewing drafts and providing feedback for the IG's consideration."
Kroloff did not immediately respond to a request for comment. Both he and Sandweg have left the department.
Sandweg resigned his position as acting ICE director earlier this year and Kroloff left before Napolitano's departure to lead the University of California last year.
Kroloff is a partner in security and intelligence consulting firm with former Secret Service Director Mark Sullivan, who retired from the agency last year.
Follow Alicia A. Caldwell on Twitter at www.twitter.com/acaldwellap
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