Presidential candidate and Sen. Rand Paul (R-Kentucky) has been raising eyebrows lately by predicting that a "secret" Hillary Clinton scandal will soon derail the former secretary of state's Democratic bid for the White House.

The New York Times reported Sunday night that Paul was referring to a new book by Peter Schweitzer, "Clinton Cash: The Untold Story of How and Why Foreign Governments and Businesses Helped Make Bill and Hillary Rich."

According to The Times, the tome is "proving the most anticipated and feared book of a presidential cycle still in its infancy."

Schweizer, described as a former conservative political operative, will reportedly connect the Bill, Hillary & Chelsea Clinton Foundation's foreign donors to special favors delivered by Clinton's State Department.

The author will also attempt to tie the Clintons' lucrative speaking fees to government favors.

"His examples include a free-trade agreement in Colombia that benefited a major foundation donor’s natural resource investments in the South American nation, development projects in the aftermath of the Haitian earthquake in 2010, and more than $1 million in payments to Mr. Clinton by a Canadian bank and major shareholder in the Keystone XL oil pipeline around the time the project was being debated in the State Department," The Times' Amy Chozick reported.

The book's promotional materials label it a "blockbuster exposé."

"Schweizer detailed patterns of official corruption in Washington that led to congressional resignations and new ethics laws. In 'Clinton Cash,' he follows the Clinton money trail, revealing the connection between their personal fortune, their 'close personal friends,' the Clinton Foundation, foreign nations, and some of the highest ranks of government," its Amazon description promises.

"Meticulously researched and scrupulously sourced, filled with headline-making revelations, 'Clinton Cash' raises serious questions of judgment, of possible indebtedness to an array of foreign interests, and ultimately, of fitness for high public office," it continues.

Then-Secretary of State Hillary Clinton with Saudi officials in 2012. Brendan Smialowski/Pool/Reuters

The Clinton campaign dismissed the Schweizer book, however, for "twisting previously known facts into absurd conspiracy theories," The Times reported.

Clinton campaign spokesman Brian Fallon connected the new Clinton book, out May 5, to previous books last year that made a number of dubious claims about the Clinton family. At one point last summer, Clinton spokesmen issued a joint statement calling three different books "complete crap." And at another point a Clinton insider harshly criticized author Ed Klein for his "despicable" lies.

Fallon said Schweitzer's work "will not be the first work of partisan-fueled fiction about the Clintons’ record, and we know it will not be the last."

Regardless, Clinton's foundation and personal wealth are likely to repeatedly show up again in Republican attacks, which have been fed by a number of controversies. As part of its reported $2 billion fundraising effort, for example, the foundation took $500,000 from Algeria at the same time the country was lobbying the State Department over its human rights issues. This reportedly broke a deal the foundation made with the White House over such foreign donations.

Additionally, Paul and others have attacked Clinton over contributions Saudi Arabia gave to the foundation. Last month, Paul called on the foundation to return millions of dollars back to the Saudi government, which he noted has a dismal record on women's rights.

The Clintons have defended their foundation's work by pointing to its beneficial projects around the globe. When pressed on its Algeria contribution, for example, the foundation noted the "unsolicited" donation came "immediately following the devastating earthquake in Haiti on January 12, 2010."

Last updated with additional context on 12:01 p.m.