Republicans on two leading House committees have released a 150-page report they say proves the Obama administration funded an Obamacare cost-sharing program illegally.

Even though Treasury lawyers concluded in 2012 that payments for the cost-sharing program and the healthcare law's insurance subsidies can't come from the same fund, the administration prepared a legal memo explaining its justification for doing so and Treasury Secretary Jack Lew authorized the IRS to administer both subsidies the same way, according to the report.

House Republicans have already sued the administration over the issue, contending that the Obama administration should have gotten a funding allocation from Congress before awarding the money to the cost-sharing program, which gives low-income Americans extra help in covering co-payments when visiting the doctor.

A federal judge ruled in May that the administration gave insurance companies the cost-sharing money without constitutional authority, but stayed the decision pending appeal. The administration filed a notice on Wednesday to challenge the initial decision.

The report released this week is the result of an extensive investigation by Republicans into how the administration funneled money into the cost-sharing program, which has received about $7 billion so far. It was released by the Ways and Means and Energy and Commerce committees, which are also holding hearings on the matter Thursday and Friday.

Committee leaders said that not only did they find the money was awarded inappropriately, but the administration also refused to comply with subpoenas and withheld information by invoking the deliberative process privilege.

"For nearly a year and a half, we have sought the most basic facts about the source of funding for this program," Ways and Means Chairman Upton and Chairman Kevin Brady said in a statement. "Along the way, we've been met by repeated roadblocks from the administration, and the refusal to share even basic information with our committees."

"Despite this administration's unprecedented obstruction, the committees have uncovered concerning new information — released today for the first time — about the administration's decision to unconstitutionally fund the CSR program without an appropriation from Congress," he said.

Democrats pushed back, saying Republicans were just trying to undermine the Affordable Care Act, as they've tried to do for years.

"Clearly there is no end to the lengths Republicans will go to undermine the Affordable Care Act," said Ways and Means ranking member Sander Levin and Energy and Commerce ranking member Frank Pallone in a statement. "Their notion that the administration obstructed yet another partisan Congressional 'investigation' is absurd, especially after the administration has provided more than a dozen government officials for hours of interviews."