The chairman of the House Oversight and Government Reform Committee asserted Monday that Iraq security contractor Blackwater USA “may have engaged in significant tax evasion.”

The lawmaker noted that the issue came up when Prince testified before his panel earlier this month. At the time, Prince said that guards like the “flexibility” of the independent contractor status and that it is a “model that works.” The IRS ruling was not mentioned and Waxman said there is “evidence that Blackwater has tried to conceal the IRS ruling and the evasion of taxes from Congress and law enforcement officials.”

The lawmaker stated that his panel has found out that “Blackwater required this employee to sign a non-disclosure agreement before it agreed to pay the back pay and other compensation that he was owed. The terms of this agreement explicitly prohibited the guard from disclosing any information about Blackwater to ‘any politician’ or ‘public official.’ ”

Waxman charges that “it now appears that Blackwater used this illegal scheme to avoid millions of dollars in taxes and then prevented the security guard who discovered the tax evasion from contacting members of Congress or law enforcement officials.”

Waxman is calling on Prince to provide the committee with documents regarding the issue, including all communications between the government and Blackwater with regard to the classification of the company’s employees, non-disclosure agreements and documents related to the security guard who requested the IRS ruling.

The panel also set up a tipline to allow people with knowledge of Blackwater’s potential tax evasion to come forward.

Blackwater officials could not be reached for comment.