WASHINGTON, Dec. 16 - A senior scholar at the Cato Institute, the respected libertarian research organization, has resigned after revelations that he took payments from the lobbyist Jack Abramoff in exchange for writing columns favorable to his clients.
The scholar, Doug Bandow, who wrote a column for the Copley News Service in addition to serving as a Cato fellow, acknowledged to executives at the organization that he had taken money from Mr. Abramoff after he was confronted about the payments by a reporter from BusinessWeek Online.
"He acknowledges he made a lapse in judgment," said Jamie Dettmer, director of communications at Cato. "There's a lot of sadness here."
Copley suspended Mr. Bandow's column.
Efforts to reach Mr. Bandow through the Cato Institute and at home were unsuccessful.
The revelation caps a year of disclosures about partisan payments to seemingly independent writers, including Armstrong Williams, the conservative columnist and television host, who received payments from the federal Education Department at a time when he was promoting the Bush administration's education policies in his columns. The administration has been under mounting pressure to become more transparent in its communications after accounts that it paid for and printed articles in Iraqi periodicals as part of its overseas propaganda effort.
Mr. Bandow did not take government money, but the source of his payments - around $2,000 an article - is no less controversial. His sometime sponsor, Mr. Abramoff, is at the center of a far-reaching criminal corruption investigation involving several members of Congress, with prosecutors examining whether he sought to bribe lawmakers in exchange for legislative help.
A second scholar, Peter Ferrara, of the Institute for Policy Innovation, acknowledged in the same BusinessWeek Online piece that he had also taken money from Mr. Abramoff in exchange for writing certain opinion articles. But Mr. Ferrara did not apologize for doing so. "I do that all the time," Mr. Ferrara was quoted as saying. He did not reply to an e-mail message seeking comment on Friday.
At Cato and similar institutions, adjunct scholars are not always prohibited from accepting outside consulting roles. But at Cato, said Mr. Dettmer, and at the American Enterprise Institute, said a spokeswoman there, rules require scholars to make public all their affiliations, and there is an expectation that scholars will not embarrass the institution.
"Our scholarship is not for sale," Mr. Dettmer said.
Glenda Winders, the vice president and editor of the Copley News Service, said in a statement that the company was immediately suspending Mr. Bandow's column pending further review.
Mr. Abramoff, who built a powerful lobbying business largely through his affluent Indian tribe clients in the late 1990's, paid Mr. Bandow during those years to advance the causes of such clients as the Commonwealth of the Northern Mariana Islands and the Mississippi Band of Choctaw Indians.
In one column in 2001, Mr. Bandow extolled the free-market system that had allowed the Marianas to thrive, saying that fighting terrorism was no excuse for "economic meddling" - the same position that Mr. Abramoff was being paid to advance.
The federal government "should respect the commonwealth's independent policies, which have allowed the islands to rise above the poverty evident elsewhere throughout Micronesia," Mr. Bandow wrote.
In an earlier column, in 1997, Mr. Bandow defended the gambling enterprise of the Choctaws. "There's certainly no evidence that Indian gambling operations harm the local community," he wrote.
Mr. Abramoff, whose work has already been the subject of Senate hearings, is suspected of misleading the tribes about the way he used tens of millions of dollars in payments. He has been indicted in a separate case in Florida, where he is scheduled to stand trial on Jan. 9 on charges of defrauding a lender as he tried to buy a fleet of gambling boats.
Although Mr. Abramoff has not yet been charged in connection with any lobbying case, his money is considered so tainted that on Friday, for a second time this week, a member of the Senate who had received large political contributions from Mr. Abramoff's clients and partners announced that he was returning the money.
The latest announcement came from Senator Conrad Burns, Republican of Montana, who is up for re-election next year and who said he would return about $150,000 in contributions from Mr. Abramoff, his clients and his associates. Earlier in the week, Senator Byron L. Dorgan, Democrat of North Dakota, said he was returning $66,000 in contributions from Mr. Abramoff's partners and Indian tribe clients.
"The contributions given to my political committees by Jack Abramoff and his clients, while legally and fully disclosed, have served to undermine the public's confidence in its government," Mr. Burns said in a statement. "From what I've read about Jack Abramoff and the charges which are pending or about to be brought against him, he massively deceived and betrayed his clients."