Legal questions swirl around idea to offer $50 million penthouse to Putin in Trump Tower Moscow originally appeared on abcnews.go.com

A pair of Trump associates discussed offering the penthouse apartment in Trump Tower Moscow to Russian President Vladimir Putin, a source familiar with the prospective deal told ABC News, which would have amounted to a $50 million gift to one of the United States' key geopolitical adversaries.

Felix Sater, who scouted deals for the Trump Organization, and Michael Cohen, Trump’s longtime attorney and confidant, conceived of the plan in 2015, the source said, calling it a marketing ploy to drive interest in their massive new Trump-branded development, which was designed to be the tallest building in the world.

PHOTO: President Donald Trump's former lawyer Michael Cohen exits Federal Court after entering a guilty plea in New York, Nov. 29, 2018. (Andrew Kelly/Reuters) More

But if the Trump Organization ever pitched the proposal to the Kremlin with an intention to curry favor with Russian officials, it could be grounds for a federal bribery case under a law called the Foreign Corrupt Practices Act (FCPA), several legal experts told ABC News.

Neither Sater nor Cohen has said publicly if the offer was ever floated to the Kremlin. In court filings detailing his plea agreement with special counsel Robert Mueller, Cohen admits that he communicated with the office of the Russian president in January 2016, specifically the personal assistant to Dmitry Peskov, Vladimir Putin's press secretary.

(MORE: Michael Cohen pleads guilty to lying to Congress in new deal with Mueller in Trump-Russia probe)

"Short of being a canvas bag of money, this sounds like a high value gift to a government official for the purpose of gaining an improper business advantage," said Mark Matthews, a former financial crimes prosecutor with the Department of Justice who is now in private practice at Caplin & Drysdale. "A scenario like this raises all the classic warning signs of a foreign corrupt practices act violation."

PHOTO: The Trump Tower logo is pictured in New York, May 23, 2016. (Carlo Allegri/Reuters, FILE) More

A source close to the Trump Organization told ABC News the penthouse idea sounds to him like "pure fantasy."

(MORE: Trump signed letter of intent for Russian tower during campaign, lawyer says)

"No one at company ever heard of any of this until reading it in the press," said the source, who asked not to be named because he was not authorized to discuss the matter. "It all appears to come from a private communication between these two individuals. The project never even got past a non-binding letter of intent. It never went anywhere."

(MORE: Trump calls potential 2016 Moscow deal 'very legal,' 'very cool' in renewed defense)

Last summer, the public first learned that Cohen had been pursuing a deal to build a Trump Tower in Moscow even after his boss had begun to campaign for president. At the time, Cohen told members of Congress the deal never progressed beyond an initial "letter of intent" and it was halted in January of 2016, before the Iowa caucuses.

PHOTO: President Donald Trump waves during the G20 Leaders' Summit family photo on Nov. 30, 2018 in Buenos Aires, Argentina. (Alexander Nemenov/AFP/Getty Images) More

Last week, however, Mueller's team released a plea agreement with Cohen in which he admits those discussions went on well past January, until at least June of 2016, and the discussions included multiple conversations with then-candidate Trump and members of his family who work at the global real estate firm.

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