Marty Davis, the wealthy Minnesota head of a kitchen countertop manufacturing company, is a steadfast supporter of former President Donald J. Trump. He contributed hundreds of thousands of dollars to help elect Mr. Trump in 2020, and encouraged him to fight to overturn the 2020 election results.

Shortly after Mr. Trump’s social media company said in October 2021 that it planned to go public by merging with a cash-rich shell company, Mr. Davis was one of the first to lend the fledgling business millions so that it could stay afloat until its merger closed and finance the launch of its Truth Social platform.

Mr. Davis gave Trump Media & Technology Group a $5 million loan, according to documents reviewed by The New York Times. His loan was part of $40 million Trump Media raised from more than a dozen private investors, some of whom have helped finance efforts to elect Mr. Trump and are now likely shareholders of his social media company.

It’s not uncommon for start-ups to seek out wealthy investors for financing, but the stock holdings raise questions about the potential for conflicts of interest and undue influence over Mr. Trump should he return to the White House.

Other early backers include two Texas billionaires, a Florida hedge fund manager, and a trust with ties to a Russian American owner of an offshore bank who is the nephew of a former high-ranking Russian government official, the documents show. One of the billionaires, Kenny Troutt, a retired Dallas telecommunications executive, has given more than $1.1 million to efforts backing Mr. Trump’s three White House bids. Mr. Troutt is serving as a co-chair of a major fund-raiser on Saturday in Palm Beach, Fla., for the former president.

“It was the deal of the century,” said Massimo D’Angelo, a lawyer for Patrick Walsh, a Florida hedge fund manager who lent $6.2 million to Trump Media.

When Trump Media finally went public in March after closing its merger with Digital World Acquisition Corp., those early investors stood to profit handsomely: Most of the loans were designed to convert into shares at around $22 a piece, whereas Trump Media shares traded around $40. It’s unclear if any of them have cashed in by selling their shares.

Some Trump Media backers like Mr. Walsh have little or no political connection to the former president. For instance, Karl Pfluger, an oil and gas billionaire who was one of the biggest lenders to Trump Media, provided nearly $10 million, is a significant donor to Republicans in Texas but not a prominent Trump donor.

Shannon Devine, a Trump Media spokeswoman said: “The media should be wary of relying on documents supplied by detractors of our company who have a history of providing outdated, deceptive and manufactured records to the press.”

Mr. Davis declined to comment. Mr. Pfluger, who is president of Oryx Midstream Services, an oil pipeline company, did not respond to a request for comment. An executive at Mr. Troutt’s family office, who signed the loan agreement, declined to comment. Mr. Troutt, who now breeds racehorses, made his $3 million loan to Trump Media through an affiliated company.

Mr. Trump, who owns 57 percent of Trump Media, did not personally put a significant amount of money into getting the company off the ground.

Ethics experts have said if Mr. Trump wins the White House and fails to divest himself of his stake in Trump Media, it could open up an entirely new avenue for foreign actors or special interests to try to curry favor with him, including by buying advertising on Truth Social.

At last count, Mr. Trump’s stake was worth about $3 billion. Trump Media itself is currently valued at around $5 billion even though it lost $58 million last year and earned just $4.1 million from advertising on Truth Social, its sole source of revenue.

Roy Bailey, the co-chair of Mr. Trump’s 2020 campaign who helped to raise some of the financing for Trump Media, declined to discuss any of the lenders. Mr. Bailey’s Dallas-based firm lent at least $33,000 to Trump Media, according to a loan agreement seen by The Times.

Wes Moss and Andy Litinksy, two of the founders of Trump Media, oversaw the fundraising from outside investors. The two men were former contestants on Mr. Trump’s reality television show “The Apprentice.” They had pitched Mr. Trump on the idea of starting the company in January 2021 after he was booted off Twitter, now called X, in the aftermath of the Jan. 6 riot at the Capitol.

Mr. Moss and Mr. Litinsky had signed most of the loan agreements on behalf of Trump Media, but are no longer associated with the company. They are feuding in court with Trump Media to maintain their roughly 6 percent equity stake in the company.

A lawyer for both men declined to comment.

The loan agreements reviewed by The Times were provided by Stephen Bell, Philip Brewster and Patrick Mincey, lawyers for a former Trump Media employee, William Wilkerson. The agreements were included in thousands of pages of documents supplied to the Securities and Exchange Commission in connection with a whistle-blower complaint filed by Mr. Wilkerson. The regulator was investigating whether Digital World had violated securities laws by engaging in premature merger talks with Trump Media. Last summer Digital World reached a settlement with the S.E.C. and agreed to pay an $18 million penalty.

Mr. Davis, the Minnesota businessman, gave Trump Media a $5 million through an obscure limited liability company. He is one of Trump Media’s more high-profile financial backers.

A longtime Republican donor, Mr. Davis successfully lobbied the Trump administration to impose tariffs on quartz from China in order to counter what he said was damage to his company from illegal dumping. Although he did not contribute to Mr. Trump’s campaign in 2016, he gave about $350,000 toward efforts to re-elect Mr. Trump in 2020. In October 2020, he hosted a $100,000-a-person fund-raiser for Mr. Trump at his Minnesota home.

His efforts to push Mr. Trump to fight the results of what he called a “corrupt election” came to light during a congressional investigation of the Jan. 6 uprising at the Capitol. In a Dec. 9, 2020 text message to Mark Meadows, then White House chief of staff, Mr. Davis said he needed an Oval Office meeting with the president to “tell him what I’m doing to fight now for him!” He added: “Also, heavily support 2024 if he gets screwed.”

A week later, he texted Mr. Meadows again, saying that he told Mr. Trump there was widespread illegal voting in Minnesota — a claim that state election officials refuted.

The most curious of all the investors in Trump Media is a entity called ES Family Trust that lent up to $8 million in late 2021 and early 2022. The trust has ties to Anton Postolnikov, a Russian American financier who lives in South Florida. Divorce records for Mr. Postolnikov and his wife, reviewed by The Times, suggest a financial connection to the ES Family Trust.

As late as last year, Mr. Postolnikov was the principal owner of Paxum Bank, a small bank based in the Caribbean island of Dominica that wired some of the loan money to Trump Media, according to documents reviewed by The Times. The bank processes payments for adult entertainment companies.

Mr. Postolnikov is the nephew of Aleksandr Smirnov, who served as a high-ranking Russian government official for almost 15 years. As of two years ago, he was the deputy head of a state-owned enterprise governing seaports.

A statement published on Mr. Postolnikov’s behalf last year denied that he was connected in any way to allies of President Vladimir V. Putin of Russia and said Russian websites were spreading lies about him. Mr. Postolnikov drew scrutiny in an insider-trading investigation by federal prosecutors who looked into trading of Digital World securities around the time of the merger announcement in 2021, according to a filing in connection with the matter. He was not charged with any wrongdoing and his lawyer declined to comment.

Kitty Bennett, Rachel Shorey and Oleg Matsnev contributed research.