Former President Bill Clinton repeatedly turned down offers to speak at Czech model Petra Nemcova's annual charity event and only accepted after she directly offered to donate $500,000 to the Clinton family's charitable organization, according to The New York Times.

Nemcova's school-building charity, the Happy Hearts Fund, held the event last year in Manhattan to raise funds to help people affected by the 2004 Indian Ocean tsunami, which she survived by clinging to a palm tree, as well as the 2010 Haiti earthquake.

The charity's former executive director told the Times that Clinton only agreed to attend the June 2014 event after the charity offered to donate $500,000 of the gala's proceeds to the Clinton Foundation, in what she described as a "quid pro quo" transaction.

"The Clinton Foundation had rejected the Happy Hearts Fund invitation more than once, until there was a thinly veiled solicitation and then the offer of an honorarium," Sue Veres Royal told the newspaper. "Petra called me and said we have to include an honorarium for him - that they don't look at these things unless money is offered, and it has to be $500,000."

Nemcova sent an updated invitation letter to Clinton at the end of August, offering to work around his schedule and proposing the donation. The letter, obtained by the Times, reads: "Understanding the need and commitment to 'rebuilding better,' Happy Hearts Fund would like to also share the proceeds of the event with the Bill, Hillary and Chelsea Clinton Foundation, committing at least $500,000 in partnership on a joint educational project in Haiti, of your selection," signed, "Lots of Love, Light and Laughter."

Press officials for the two organizations told the Times on Thursday that no solicitation had been made, and that the money would be used for as of yet undetermined projects in Haiti.

Doug White, director of Columbia University's master's program in fundraising management, told the Times the arrangement was both revealing and distasteful, especially considering the Clinton Foundation is said to have raised $2 billion.

"This is primarily a small but telling example of the way the Clintons operate," White said. "The model has responsibility; she paid a high price for a feel-good moment with Bill Clinton. But he was riding the back of this small charity for what? A half-million bucks? I find it - what would be the word? - distasteful."

The Clinton Foundation's alleged pay-to-play modus operandi has come under intense scrutiny since former Secretary of State Hillary Clinton announced her 2016 presidential campaign. Critics claim foundation donors received preferential treatment from her during her time as the nation's top diplomat. It was revealed last month that Bill Clinton accepted more than $2.5 million in speaking fees from 13 major corporations and trade associations while they were also lobbying Hillary's State Department in pursuit of preferred policy, according to the International Business Times (IBT). And last week, IBT reported that Hillary's State department approved more than $300 billion worth of arms sales to 20 nations whose governments had at some point given to the Clinton Foundation.

"The word was out to these groups that one of the best ways to gain access and influence with the Clintons was to give to this foundation," Meredith McGehee, policy director at the Campaign Legal Center, told IBT.