Former President Clinton’s nonprofit foundation, the William J. Clinton Foundation, raised more than $135-million last year, a 70-percent increase over 2005.

The influx of donations helped the foundation put more money into its HIV/AIDS-prevention efforts and environmental-policy programs, as well as providing support for the Clinton presidential library in Little Rock and the Bush-Clinton Katrina Fund.

Critics, however, are concerned that donors may be buying political influence as the president’s wife, Senator Hillary Rodham Clinton, continues her bid for the 2008 presidency, reports the Associated Press.

Since the foundation is not required by law to release information about donors, and the organization’s tax forms do not identify contributors by name, some critics say that the foundation could potentially provide a mechanism for corporations and donors from foreign countries to effectively circumvent federal campaign-finance laws.

Massie Ritsch, a spokesman for the Center for Responsive Politics, said, “This creates potential conflicts of interest because donors to the presidential libraries may be giving so they can curry favor and get access with the relative of the person whose name is on the library.”

Officials of the Clinton Foundation were not quoted in the article responding to that criticism.

The Clinton Foundation is one of the most successful fund-raising organizations in the United States. It ranked No. 170 on The Chronicle’s latest ranking of the 400 organizations that raised the most from private sources.

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