MSNBC host Lawrence O'Donnell says he has a source who told him Russian oligarchs signed off loans given to President Trump by Deutsche Bank.

Lawyers for the German lender told a federal appeals court Tuesday that the bank has documents sought by Democrat-led House committees, which subpoenaed Deutsche Bank and Capital One for financial records related to Trump, his family, and businesses, but declined to reveal if they have Trump's tax returns.

While the New York Times reports that Deutsche Bank, which has done business with Trump for two decades, does have some of Trump's personal and corporate tax returns, O'Donnell told colleague Rachel Maddow in the hand-off between their shows Tuesday evening he can go a bit further.

"This single source close to Deutsche Bank has told me that the Trump — Donald Trump's loan documents there show that he has co-signers. That's how he was able to obtain those loans. And that the co-signers are Russian oligarchs," he said.

A shocked Maddow replied, "What? Really?"

"That would explain, it seems to me, every kind word Donald Trump has ever said about Russia and Vladimir Putin, if true, and I stress the 'if true' part of this," O'Donnell added.

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O'Donnell later said this source told him that Trump's tax returns reveal "he pays little to no income tax in some years."

He added that his source said Trump, a longtime real estate businessman, would not have been able to obtain his loans with Deutsche Bank without these co-signers he described as "Russian billionaires close to Vladimir Putin."

"If true," O'Donnell said, "that would be a significant factor in Vladimir Putin's publicly stated preference for presidential candidate Donald Trump over presidential candidate Hillary Clinton."