Hillary Clinton's family foundation got a seven-figure cash infusion in 2008 from murky sources in India just before she cast a U.S. Senate vote to support ending an embargo on the trade of U.S. nuclear technology on the subcontinent.

The story, well-known at the time, has new life in light of 'Clinton Cash,' a book that has dogged the former senator and secretary of state since its conflict-of-interest allegations first surfaced this month.

Peter Schweizer, the book's author, laid out a scenario Tuesday on the MSNBC program 'Morning Joe,' that suggests Clinton was swayed in her vote by the donation of between $1 million and $5 million from Amar Singh, then the general secretary of India's Samajwadi Party.

Singh, it turned out, was merely a pass-through vehicle for the funds.

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TRANSACTIONS: Amar Singh (left) and Hillary Clinton are pictured in 2009, months after his lobbying helped persuade her to abandon her objections to an Indo-American nuclear deal; Peter Schweizer's book 'Clinton Cash' argues that Singh's seven-figure donation to the Clinton Foundation helped grease the wheels

OLD BUDDIES: Former president Bill Clinton (center) traveled to India in 2005 to attend a launch party for a rural health program overseen by Amar Singh (left); the two are pictured with then-Chief Minister of Uttar Pradesh Mulayam Singh Yadav (right)

If it were his own money, Schweizer told the New York Post, that would mean 'Singh had given between 20 and 100 percent of his entire net worth to the Clinton Foundation!'

He 'admits now,' the author said Tuesday, 'that his donation to the Clinton Foundation wasn't even his money.'

The Times of India reported in December 2008 that Singh admitted as much.

'I have nothing to say. I won't deny anything,' he initially told reporters.

But moments later Singh acknowledged that the 'payment could have been made by someone else on his behalf.'

Later, Schweizer writes in his book, Singh told Indian government officials that the Clinton Foundation listed his name 'erroneously' as a donor on its financial discloures.

He had 'facilitated the payment,' he said, according to the book.

Singh visited with Hillary on Capitol Hill in September 2008. She later cast a vote – abandoning her own previous opposition – in support of opening a flood of nuclear technology to New Delhi.

Peter Schweizer outlined a series of events on Tuesday that he compared to insider-trading deals, which leave circumstantial evidence in their wake that builds up over time

'I have had a very close relationship with Hillary Clinton,' Singh told the Indian expat website Rediff India Abroad at the time.

'I had a dinner appointment with her yesterday night, where we spent some quality time together for more than two hours.'

Peter Schweizer's book, 'Clinton Cash,' is due in stores on May 5

He said lobbying her on the Indo-American nuclear matter was 'the sole purpose of my visit.'

But his ties to the former first family go back to at least 2005, when Bill Clinton traveled to India to attend a launch party for a rural public health initiative overseen by Singh.

Clinton was accompanied on that trip by Sant Singh Chatwal, am Indian hotel tycoon who had introduced the two.

The Post notes that Hillary Clinton’s financial links with India and Indian-Americans were well established when she ran for president in 2008.

At one point then-Senator Barack Obama apologized to her after a campaign staffer made a joke in a memo – referring to her as '(D-Punjab).'

Schweizer, president of the Government Accountability Institute, on Tuesday spelled out the context of what he said were donations from 'a number of Indian interests' to Clintonworld.

'In 1998 the Indian government conducted nuclear tests; Bill Clinton imposed restrictions on the export of U.S. nuclear technology, because this violated the nonproliferation treaty,' he recalled.

'Hillary Clinton supported that position.'

'In 2005, the Indian government wanted those restrictions lifted,' Schweitzer said. 'Hillary Clinton at that time supported a killer amendment to stop that from happening.'

'After 2005, a number of Indian interests, including an Indian politician that admits now that his donation to the Clinton Foundation wasn't even his money – those donations flowed. In 2008, she reverses course, and supports the export of US nuclear technology.'

'And by the way,' Schweizer added, 'her her top aides Bob Einhorn, and others – her top advisers on nonproliferation – were still opposed to that agreement.'

The Singh story is the latest in a series of faucet-drips that threaten to derail Clinton's bid to claim the U.S. presidency in 2016.

'Money flows to the Clintons, either through speaking fees or Clinton Foundation donors,' Schweizer said Tuesday, and 'Hillary Clinton takes a course of action that benefits those donors'

Schweizer's book has lobbed other stinging allegations at her – including one surrounding a uranium deal that she green-lighted whiel secretary of state.

That arrangement, inked after the Clinton Foundation took in more than $31 million from one of its stakeholders, triggered a series of buyouts that left the Russian government in control of much of America's uranium resources – at a tie when Vladimir Putin's government is allegedly sharing nuclear technology with Iran.

'I can't look into Hillary Clinton's mind,' Schweizer told MSNBC host Joe Scarborough on Tuesday. 'I certainly can't look at her emails. I don't have any of those capabilities.'

'But I would compare it to, like, insider trading. When they prosecute people for insider trading, lots of times they don't have a smoking gun, but they see a series of well-timed trades.'

'You look at a series of actions in which money flows to the Clintons, either through speaking fees or Clinton Foundation donors,' he said. 'Hillary Clinton takes a course of action that benefits those donors. In many cases, I think – outlined in the book – she is reversing course on policy prescriptions.'