Bush administration officials were wrong to prevent a budget expert from giving Congress estimates of the cost of Medicare (search) legislation, congressional researchers have concluded.

In a report made public Monday, the nonpartisan Congressional Research Service (search) said efforts to keep Richard Foster, the chief Medicare actuary, from giving Democratic lawmakers his projections of the bill's cost - $100 billion more than the president and other officials were acknowledging - probably violated federal law.

Recent estimates set the bill's cost at more than $500 billion.

Foster testified in March that he was prevented by then-Medicare administrator Thomas Scully (search) from turning over information over to lawmakers. Scully, in a letter to the House Ways and Means Committee, said he had told Foster "that I, as his supervisor, would decide when he would communicate with Congress."

Congressional researchers chided the move. "Such 'gag orders' have been expressly prohibited by federal law since 1912," Jack Maskell, a CRS attorney, wrote in the report.

The report was requested by committee Democrats after majority Republicans refused to subpoena Scully and White House adviser Doug Badger to testify about their roles in keeping cost estimates from lawmakers.

Rep. Bill Thomas, R-Calif., the committee chairman, said he would be willing to issue subpoenas if laws had been broken.

A spokesman for Thomas did not immediately respond to requests for comment.