Three years after the William J. Clinton Presidential Library opened its doors, the list of donors who helped the former president build his $165 million complex remains a secret from the public. Yet the Blotter on ABCNews.com has learned that the Clinton Foundation sold portions of the list through a data company headed by a longtime friend and donor. "The fact that they’ve sold the list and then turned around and said that these names must be kept anonymous completely undercuts their argument," said Sheila Krumholz of the Center for Responsive Politics, a Washington, D.C.-based government watchdog group that tracks the influence of money in politics. An employee of Walter Karl, a subsidiary of the data company InfoUSA, told ABCNews.com that the company made a list of more than 38,000 donors to the Clinton presidential library available for sale to foundations and other nonprofit groups from June 2006 to May 2007. A spokesman for the company would not say how the profits from the sale of the partial list were distributed. See the Walter Karl listing. There is no legal requirement for presidential libraries to disclose the identities of their contributors. Donors, including corporations and foreign governments, can give unlimited amounts while the president is still sitting in office. THE BLOTTER RECOMMENDS Photos Trouble on the Campaign Trail Primetime Video Heated Exchange: Clinton and Jennings Full Blotter Coverage Norman Hsu, Clinton Fundraiser Click Here for Full Blotter Coverage "This is one of the few places that remain under the veil of secrecy, and there is really no good reason for it," says Krumholz. "Disclosure is important because the money is often being raised while the president is in office, and in this case and with the Bush family, they can be given for currying favor with persons other than the president being honored." "I don’t think I should disclose it unless there is some conflict of which I am aware of, and there is not," said former President Bill Clinton at a news conference in September after his wife, Sen. Hillary Clinton, was questioned about the donor list at a presidential debate. "A lot of people gave me money with the understanding that they could give anonymously. And if they gave publicly, they would be the target for every other politician in America." The former foundation chairman Skip Rutherford says that when the foundation started soliciting funds, it adopted the policy of the Reagan library to leave disclosure up to donors. "People were told that we would not disclose their gifts," said Rutherford. "Disclosure was up to the donor; if the donors chose to do so, it was their prerogative. Some did; others didn’t." The George Bush Presidential Library and Museum voluntarily disclosed a list of donors giving more than $10,000 at its opening, with the exception of a "few" who asked to remain anonymous, according to the library’s executive director Dr. Roman Popadiuk. Late in the day, the Clinton Foundation responded to the story with a statement saying, "the Foundation’s list included individuals who gave $100 or less in response to direct mail solicitations. Using the Walter Karl Company as its vendor, other entities could rent or exchange use of the Foundation’s list. The vendor independently undertakes the mailing and does not share the actual list with other entities." The little that is known about the identities of the donors to the Clinton library was reported by the New York Sun in 2004, after a reporter discovered the names on a touch-screen computer on the third floor of the library after its opening. Members of the Saudi royal family, Arab businessmen, the governments of Dubai, Kuwait, Qatar, Brunei and Taiwan, and Hollywood celebrities, were among the 57 individuals or foundations who gave $1 million or more to the library, according to the Sun. The computer with the list of donors was disconnected after the Sun article ran. At the time, Clinton officials said that a permanent list of donors contributing $100,000 or more would eventually be installed on a wall at the library. Bill Rollnick, the former chairman of Mattel and a longtime Clinton supporter who was among those contributing $1 million or more, said he didn’t think the donor list was "anybody’s business." "If they want to make it public, that’s their business," said Rollnick. "There’s nothing nefarious about it — it’s just a library."Vin Gupta, CEO of InfoUSA, was also on the list of donors giving $1 million or more. His ties to the Clintons came under scrutiny earlier in the year when a lawsuit filed by InfoUSA shareholders accused Gupta of wasting millions of dollars of the company’s money to "ingratiate himself" with the Clintons and other personal friends. Separately, a New York Times article in May revealed that InfoUSA was involved in an investigation in Iowa for selling mailing lists of elderly Americans to criminals. In response to the investigation, the company released a statement saying, "While InfoUSA can not manage what a client does with the publicly available information InfoUSA provides, the company has a strict policy about not selling data to companies who act illegally." Gupta has donated and raised millions of dollars for the Clintons’ political campaigns and charities over the last decade. InfoUSA spent millions more paying the former president as a consultant and flying him and his wife to events around the country and family vacations in Hawaii and Acapulco, Mexico on the company’s private jet, according to the court documents. InfoUSA officials have stated that the expenses were "legitimate business expenses." Read Vin Gupta’s statement. A spokesman for Sen. Clinton said in May that InfoUSA had been reimbursed for her flights, though ethics rules at the time only required the reimbursement be equal to the cost of first-class airfare. This post has been updated. Do you have a tip for Brian Ross and the Investigative Team?