The General Accountability Office is launching an investigation into the Education Department's deal with a black conservative columnist, who promoted Bush administration policies after receiving a payment of $240,000.

Armstrong Williams (search), a leading black conservative voice, has already been dropped by a major syndication service because he accepted the money. Williams called criticism of his relationship with the department "legitimate."

Last week, Sens. Edward Kennedy (search), D-Mass., and Frank Lautenberg, D-N.J., requested that the GAO probe the department's deal with Williams. On Friday, the GAO told Lautenberg's office that they sent a letter to the Education Department officially notifying it of the investigation.

The news of the probe comes as the Department of Health and Human Services revealed a third columnist had been paid to promote Bush policies.

The Education Department received the GAO's letter and is reviewing it, said department spokeswoman Susan Aspey. "Secretary Spelling has made it very clear she is getting to the bottom of this."

Education Secretary Margaret Spellings (search) started this week, replacing Rod Paige.

In a letter to Sens. Arlen Specter, R-Pa., and Tom Harkin, D-Iowa, dated Friday, Spellings wrote, "At this point, what I can say is that at a minimum, there were errors of judgments at the Department, and I am diligently working to get to the bottom of it all."

The lawmakers are the chairman and the ranking member of a panel that oversees education spending, and their subcommittee is looking into the matter.

Spellings also said the department has directed Ketchum to stop all work under the contract.

A contract required Williams' company, the Graham Williams Group, to produce radio and TV spots featuring one-minute "reads" by Paige and to allow Paige and other department officials to appear as studio guests with Williams.

Williams also was to use his influence with other black journalists to get them to discuss No Child Left Behind, a centerpiece of President Bush's domestic agenda, which aims to raise achievement among poor and minority children and penalizes many schools that don't make progress.

The GAO, often called the "congressional watchdog," is a nonpartisan agency working for Congress that monitors how the U.S. government spends taxpayer dollars. Federal law bans the use of public money on propaganda.

"The issue here isn't just whether a journalist violated ethics, but whether the Bush Administration broke the law," Lautenberg said Friday. "If the GAO finds that the payment to Armstrong Williams was an illegal use of taxpayer dollars, then the money should be returned and Education Department officials should be held accountable."

Earlier this month, Tribune Media Services (search) said it told Williams that it was halting distribution of his weekly newspaper column.

The company, a subsidiary of the Tribune Co., said it accepted his explanation that the payment was for advertising on his radio and television programs.

"Nevertheless, accepting compensation in any form from an entity that serves as a subject of his weekly newspaper columns creates, at the very least, the appearance of a conflict of interest. Under these circumstances, readers may well ask themselves if the views expressed in his columns are his own, or whether they have been purchased by a third party," a statement said.

The National Association of Black Journalists (search) expressed disappointment in Williams, who is not a member of the group.

"I thought we in the media were supposed to be watchdogs, not lapdogs," said NABJ Vice President-Print Bryan Monroe, assistant vice president-news at Knight Ridder. "I thought we had an administration headed by a president who took an oath to uphold the First Amendment, not try to rent it."

The White House has said Friday that the decisions on the contract were made by the Education Department, which has defended its decision as a "permissible use of taxpayer funds under legal government contracting procedures." The point was to help parents, particularly in poor and minority communities, understand the benefits of the law, the department said.

The radio show "The Right Side," which Williams both hosts and owns, is carried by the Lynchburg, Va.-based Liberty Channel, which is affiliated with the Rev. Jerry Falwell, by Sky Angel satellite network, a Christian organization, and by Hunt Valley, Md.-based Sinclair Broadcast Group of Hunt Valley, Md.

Information about the contract with Williams was first reported by USA Today, and Williams' Web site, www.armstrongwilliams.com, carried the text of the newspaper's article.

The Associated Press contributed to this report.