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Stormy Daniels' attorney claimed Tuesday that President Donald Trump's personal lawyer Michael Cohen received $500,000 from a company controlled by a Russian oligarch, deposited into an account for a company also used to pay off the adult film actress.

Daniels' attorney, Michael Avenatti, also detailed other transactions he said were suspicious, including deposits from drug giant Novartis, the state-run Korea Aerospace Industries, and AT&T.

Novartis confirmed it had paid Cohen's company, Essential Consultants, and said Special Counsel Robert Mueller had inquired about the arrangement in November. AT&T also confirmed it paid Cohen's company, for "insights" into the Trump administration.

Avenatti's claims, made in a dossier posted to Twitter, could suggest a new dimension to the federal investigation into Cohen. NBC News has reviewed financial documents that appear to support Avenatti’s account of the transactions.

After significant investigation, we have discovered that Mr. Trump’s atty Mr. Cohen received approximately $500,000 in the mos. after the election from a company controlled by a Russian Oligarc with close ties to Mr. Putin. These monies may have reimbursed the $130k payment. — Michael Avenatti (@MichaelAvenatti) May 8, 2018

"This thing is a pig and they can try to put lipstick on a pig — tonight, next week, next month — but it's still gonna be a pig," Avenatti said on MSNBC's "The Last Word with Lawrence O'Donnell."

"This thing's ugly and it's gonna get worse."

Cohen disputed Avenatti's accounting but provided no details.

"His document is inaccurate," he said as he left a Manhattan hotel and got into a cab Wednesday morning.

Avenatti said his investigation uncovered that $4.4 million flowed through a First Republic account linked to Essential Consultants between October 2016 and January 2018. Essential Consultants is the company Cohen created before the 2016 election and then used to wire $130,000 to Daniels to stop her from going public with her account of an alleged sexual affair with Trump a decade ago.

In particular, Avenatti identified eight transactions between January and August 2017, totaling half a million dollars, from U.S.-based Columbus Nova, which he said is controlled by Russian billionaire Viktor Vekselberg and Vekselberg's cousin Andrew Intrater.

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In a statement, an attorney for Columbus Nova said the management firm is owned and controlled by Americans and not Vekselberg, who is the president of the Russian conglomerate Renovo Group.

"After the inauguration, the firm hired Michael Cohen as a business consultant regarding potential sources of capital and potential investments in real estate and other ventures," the Columbus Nova statement said.

"Reports today that Viktor Vekselberg used Columbus Nova as a conduit for payments to Michael Cohen are false. The claim that Viktor Vekselberg was involved or provided any funding for Columbus Nova's engagement of Michael Cohen is patently untrue.

"Neither Viktor Vekselberg nor anyone else other than Columbus Nova's owners, were involved in the decision to hire Cohen or provided funding for his engagement."

This thing is a pig and they can try to put lipstick on a pig — tonight, next week, next month — but it's still gonna be a pig.

Columbus Nova was listed on the website of the Renova Group as one of its "companies" until November 2017. Renova's website is now listed as "under construction," but older versions remain on The Wayback Machine, which creates archives of sites across the web.

In a statement, Columbus Nova's attorney said the firm "has managed assets on behalf of Renova Group companies and other clients. Columbus Nova itself is not now, and has never been, owned by any foreign entity or person including Viktor Vekselberg or the Renova Group."

A review of public election filings shows that the CEO of Columbus Nova, Andrew Intrater, made several political donations over the past two years.

According to public record filings he donated $29,600 to the Republican National Committee in June 2017, $35,000 to the Trump Victory PAC the same month, and then $250,000 to the Trump Inauguration Fund. Columbus Nova has also registered many alt-right internet domains, though the domains return an error message.

Russian President Vladimir Putin meets with Renova Group Board Chairman and Skolkovo Foundation President Viktor Vekselberg at the Kremlin in Moscow on March 14, 2017. Alexei Nikolsky / TASS via Getty Images file

Vekselberg questioned by Mueller probe investigators

As the New York Times first reported last week, citing people familiar with the matter, agents working for Special Counsel Mueller searched and questioned Vekselberg as he got off a private plane in the New York area earlier this year.

Vekselberg — one of the richest men in Russia, with a fortune from aluminum and oil — also attended a much-discussed 2015 dinner in Moscow where Michael Flynn, soon to become Trump's national security adviser, was seated next to Russian President Vladimir Putin.

Vekselberg, who was among the Russian oligarchs sanctioned by the U.S. Treasury Department last month, has not been accused of wrongdoing in connection with either Mueller's investigation of Russian meddling in the 2016 presidential election or a separate probe of Cohen by the U.S. Attorney's office in Manhattan.

He could not be reached for immediate comment.

Avenatti also said he had uncovered:

Four payments of just under $100,000 made by Novartis to Essential in late 2017 and early 2018. He noted reports that said Trump met with Novartis' CEO in January 2018. In a statement, Novartis said it had a one-year agreement with Essential Consultants, "focused on U.S. healthcare policy matters," that expired in February. It was contacted in November by Mueller's office and "cooperated fully," it said.

AT&T made four payments of $50,000 each to Essential in late 2017 and early 2018. In a statement, AT&T said it engaged the firm in early 2017 to "provide insights into understanding the new administration. They did no legal or lobbying work for us, and the contract ended in December 2017.”

Korea Aerospace Industries made a $150,000 payment to Essential in November 2017. KAI did not respond to requests for comment.

Nicholas Biase, a spokesperson for the U.S. Attorney’s Office in Manhattan, declined to comment on Avenatti’s report and declined to confirm its authenticity. First Republic also declined comment.

The White House has said Trump denies having an affair with Daniels, and Cohen has said he himself put up the $130,000 she was given in a non-disclosure agreement. One of Trump's new attorneys, former New York City Mayor Rudolph Giuliani, said last week that Trump repaid the money to Cohen.