Story highlights The federal appeals court found that the IRS had committed some "unconstitutional acts"

The lawsuit is separate from a two-year Justice Department investigation

Washington (CNN) A federal appeals court says the Internal Revenue Service has not proven it has ended discriminatory practices against conservative groups seeking tax-exempt status, reinstating a lawsuit against the troubled agency.

The US Court of Appeals for the District of Columbia Circuit's unanimous order on Friday reversed a 2014 lower district court ruling that previously dismissed the lawsuit, which was originally filed the year before.

The federal appeals court found that the IRS had committed some "unconstitutional acts against at least a portion of the plaintiffs," including "Be-On-The-Lookout" or "BOLO" lists where certain organizations' applications for tax-exempt status "were subjected to extended delay" and "were not receiving the same processing as those of other organizations."

Although the IRS announced that it had suspended the use of "BOLO" lists in the application process, the federal appeals court stated that the IRS' use of the word "suspend" indicated that it is not a permanent change.

Additionally, the court ruled that even if the IRS did voluntarily cease all discriminating practices, "it is absurd" to suggest the unlawful activity by the IRS has been eradicated "when two of the appellant-plaintiffs' applications remain pending."

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