Donald Trump's campaign is again on the defensive, this time after a report detailed connections between Trump campaign manager Paul Manafort and Ukraine's pro-Russia ex-president.
The report, published in The New York Times late Sunday, disclosed the existence of secret ledgers in Ukraine that show $12.7 million in cash designated for Manafort.
Manafort worked for years as a consultant for President Viktor Yanukovych and his Party of Regions before the pro-Kremlin leader was ousted in 2014, amid accusations of corruption and economic mismanagement.
Ukrainian investigators do not know whether Manafort received the payments laid out in the ledger, but believe they were part of an "illegal off-the-books system," the Times reported.
Manafort denies wrongdoing
Manafort denied receiving cash disbursements for his work in Ukraine, saying in a statement obtained by MSNBC that the allegation is "unfounded, silly and nonsensical."
"I have never received a single 'off-the-books cash payment' as falsely 'reported' by The New York Times, nor have I ever worked for the governments of Ukraine or Russia," Manafort said.
Manafort, who has worked for several controversial foreign leaders, acknowledged working as a "campaign professional" on "overseas campaigns" but said his work in Ukraine ended in 2014.
The campaign of Trump's rival, Democratic presidential nominee Hillary Clinton, has appeared eager to portray Manafort's background as evidence of Trump's pro-Russia ties.
Late Sunday, Clinton's campaign released a statement about what it said were "more troubling connections between Donald Trump's team and pro-Kremlin elements in Ukraine."
"Donald Trump has a responsibility to disclose campaign chair Paul Manafort's and all other campaign employees' and advisers' ties to Russian or pro-Kremlin entities, including whether any of Trump's employees or advisers are currently representing and or being paid by them," it said.
The statement, by Clinton campaign chair Robby Mook, said it was particularly urgent to release this alleged information "given the pro-Putin policy stances adopted by Donald Trump and the recent Russian government hacking and disclosure of Democratic Party records."
Republican presidential candidate Donald Trump speaks during a campaign rally, Aug. 10, 2016, in Abingdon, Va.
Trump's Russia comments
Trump's alleged Russia connections received more scrutiny in recent weeks, especially after the Democratic National Committee was the victim of a possible Russian cyber attack that some saw as an attempt to tilt the U.S. election in favor of Trump.
The Republican presidential nominee has made several comments about Russia in recent months that have raised eyebrows.
He praised the leadership qualities of Russian President Vladimir Putin, and said it was a "great honor" after Putin referred to him as "bright and talented." More recently, Trump called on Russia to hack Clinton's emails, a comment he later dismissed as a joke.
Last month, Trump appeared to parrot the Kremlin's justification for the 2014 annexation of Crimea, saying many in the region wanted to be a part of the Russian state anyway.
Trump has dismissed as a conspiracy the questions about his alleged Russia ties.