Deputy Homeland Security Secretary Alejandro Mayorkas fostered "an appearance of favoritism and special access" by approving immigration applications of well-connected, wealthy foreign investors, even though officials warned Mayorkas that the investor visas should be denied, according to an inspector general report released Tuesday.

Stopping short of accusing Mayorkas of wrongdoing, the report says that while Mayorkas was head of the U.S. Citizenship and Immigration Services, he meddled in cases involving top Democrats, including former Pennsylvania Gov. Edward Rendell, Sen. Harry Reid, Virginia Gov. Terry McAuliffe and Anthony Rodham, the brother of former Secretary of State Hillary Clinton. All made personal appeals for better treatment of connected investors, reported ABC News.

The report notes that more than 15 whistleblowers complained about Mayorkas giving special treatment to connected applicants in a program that offers visas to wealthy foreigners who invest in American companies.

"The juxtaposition of Mr. Mayorkas' communication with external stakeholders on specific matters outside the normal procedures, coupled with favorable action that deviated from the regulatory scheme designed to ensure fairness and evenhandedness in adjudicating benefits, created an appearance of favoritism and special access," Inspector General John Roth concluded.

For example, Mayorkas showed "unprecedented" intervention for investors from a Las Vegas casino project championed by then Senate Majority Leader Reid, ordering that investor applications be expedited and that his agency send weekly briefings to Reid's office.

Other projects Mayorkas intervened in include McAuliffe's electric car company, GreenTech Automotive, and a series of films by Sony Pictures.

"Mr. Mayorkas communicated with stakeholders on substantive issues, outside of the normal adjudicatory process and intervened with the career USCIS staff in ways that benefited the stakeholders," the inspector general concluded. "In each of these three instances, but for Mr. Mayorkas' intervention, the matter would have been decided differently."

Mayorkas responded to the accusation with a 32-page rebuttal, claiming he was trying to correct what he thought were flaws in the program, reported The Washington Times. What the inspector general viewed as interference was actually good leadership, Mayorkas said.

"I did so not because I wanted to but because I needed to. It was not easy or pleasant to hear complaints of how poorly our agency was performing ... and how incompetent we were in the performance of some of our work," Mayorkas wrote.

"I could have taken a far easier path as the director of USCIS, assumed a more ceremonial role, traveled far and wide on trips of interest and enjoyed the perks. Instead, I worked tirelessly and tackled the agency's biggest challenges," he explained.