Last month, according to The Telegraph, the company posted a government-issued "most wanted" warning on the website's homepage, urging customers to provide information on Tibetan activists suspected of causing riots in the disputed Himalayan territory.
In 2005, Alibaba arranged for Bill Clinton to speak at a conference of Internet executives in Hangzhou, but instead of receiving a fee, which can range from 100,000 dollars to 400,000 dollars, he accepted an undisclosed donation to the William J Clinton Foundation.
A spokesman for the foundation confirmed that a donation had been received from Alibaba.
However, in her White House campaign, Hillary Clinton called on President George W Bush to skip the opening ceremony of the Beijing Olympics in August.
"The violent clashes in Tibet and the failure of the Chinese government to use its full leverage with Sudan to stop the genocide in Darfur are opportunities for presidential leadership," she said recently.
Critics and even associates of the Clintons fear that there would be huge conflicts of interest if the couple returned to the White House and Clinton acted as an international ambassador for the US, as his wife has suggested.
Earlier this year it emerged that he had helped a major donor to his foundation, which combats global poverty and Aids, gain a business deal in Kazakhstan. Against official US policy, he praised the ex-Soviet dictatorship for trying to improve its human rights.
Bill Clinton also supports a proposed free-trade deal between the US and Colombia, which his wife opposes.
News of the Chinese connection prevented Hillary Clinton from taking full advantage of a stumble by Barack Obama, her Democrat rival.
He was criticised for describing small-town voters in Pennsylvania as people who "cling to guns or religion" because they are "bitter" over job losses.