Ukrainian-American businessman Lev Parnas and his business partner were arrested in 2019, accused by the US government of funnelling a Russian oligarch’s money into American political campaigns. One recipient of Parnas’ donations – Florida Governor Ron DeSantis – has said he was barely an acquaintance.

“The governor does not have a relationship with these individuals,” DeSantis’ spokesperson at the time, Helen Aguirre Ferré, said in a statement on October 10, 2019. Six days later, DeSantis told reporters that Parnas “was just like any other donor, nothing more than that.”

But DeSantis and Parnas worked more closely together than the Republican governor has disclosed, according to a detailed account of their relationship Parnas provided to Reuters and 63 previously unreported text messages from DeSantis to Parnas between May and October 2018, as DeSantis campaigned for governor. A jury later found Parnas guilty of campaign finance crimes and other charges.

As DeSantis prepares to take a widely anticipated leap into the 2024 presidential campaign this week, the disclosures from Parnas cast new light on the Florida governor’s relationship with the businessman and the role Parnas played in helping DeSantis gain entree to the circle of former President Donald Trump.

DeSantis spokesman Dave Abrams did not respond to specific questions on the existence of the texts and Parnas’ account of their relationship. “This is another recycled narrative that has been proven wrong many times over,” he said. DeSantis gave back the contribution after Parnas ran into legal trouble.

The text messages reviewed by Reuters show that DeSantis frequently – in more than 20 texts – appealed to fellow Floridian Parnas for introductions, advice and other fundraising help during his hotly contested campaign for governor. Two sources close to DeSantis during his 2018 campaign confirmed the texter’s number belonged to DeSantis at that time.

The texts also reveal that Parnas served as an intermediary between DeSantis and former New York City Mayor Rudolph Giuliani, who at the time was the personal attorney of then-President Trump. In one case, 10 days before the 2018 election, DeSantis sent Parnas a text with suggested wording for a Giuliani tweet in support of his candidacy, the messages show.

Giuliani did not respond to questions sent through his attorney and his spokesman. Ferré, DeSantis’ former spokesperson, did not respond to requests for comment.

Parnas, now 51, shot to prominence in 2019. He was a key figure in the events leading to Trump’s first impeachment, working with Giuliani to gather damaging information on Democrat Joe Biden’s son Hunter in Ukraine.

Accused of withholding aid to Ukraine unless Kyiv investigated Biden, Trump was impeached by the Democratic-led House of Representatives and charged with abuse of power. He was acquitted by the Republican-majority Senate.

A federal judge sentenced Parnas last year to 20 months in prison on a separate matter, defrauding investors in a sham company and illegally making donations to US political candidates on behalf of Russian oligarch Andrey Muraviev. Muraviev has been charged in the case but is a fugitive. He declined to comment.

Even before his criminal case, Parnas had an unusual resume for a political rainmaker. After moving to Florida from New York in 1995, he worked for penny stock companies that ran into regulatory problems, according to public records. In 2016, a federal court in New York issued a $508,734 judgment against him for defrauding an individual whose family trust lent Parnas money for a movie, called Anatomy of an Assassin, according to the judge’s ruling. Parnas says he did nothing wrong in that case.

Parnas is serving out his sentence under house arrest. Wearing shorts and an ankle bracelet, he spoke with Reuters for several hours at his home in Boca Raton. Parnas says he now regrets his alliance with Giuliani and Trump, believing he was used.

He said he shared the texts with Reuters because he feels betrayed by DeSantis, who he says stopped returning texts or calls once he won the governor’s race. Parnas once considered DeSantis a close confidant, he said. “We became very friendly.”

In 2018, Parnas was a well-known figure in Trump’s orbit, often seen with Giuliani. Parnas and his business partner, another Ukrainian American named Igor Fruman, would later pay Giuliani $500,000 for consultant work, Reuters has reported.

Parnas said he first met DeSantis on May 9, 2018, about three months before Republican primary elections in Florida. DeSantis, then a three-term US Representative, was locked in a tight primary race for governor with Adam Putnam, Florida’s then-commissioner of agriculture.

“Ron DeSantis approached me at the Trump International Hotel and introduced himself, telling me that he was told to come meet me because I was very close with Donald Trump,” Parnas said. Reuters could not establish who told DeSantis to meet with Parnas at the Washington DC hotel.

While Trump had already tweeted support for DeSantis the prior December, DeSantis wanted a formal endorsement by Trump ahead of the August primary. “He told me he heard I was the guy to speak to because of my relationship with Trump, that’s how he worded it,” Parnas said.

There’s no evidence Parnas had any direct influence with Trump. A spokesperson for Trump did not respond to a request for comment. But Parnas conferred frequently with Giuliani. At 9:49pm that day in May 2018, DeSantis texted his cell phone and email addresses to Parnas, according to the messages reviewed by Reuters. Parnas replied by sending his own email address to DeSantis.

At their first meeting at the hotel, Parnas described himself as “a bit standoffish” with DeSantis because he hoped to launch a cannabis business and considered DeSantis hostile to legalised marijuana. In another meeting several days later, also at Trump’s hotel, DeSantis told him he was not opposed to expanding medical marijuana use in Florida, Parnas said.

Reuters could not independently corroborate the hotel meetings. One frequent hotel patron, who spoke on the condition of anonymity, said he remembered seeing DeSantis and Parnas speaking together in the lobby that May or June. The hotel has since been sold.

Parnas said Dana Rohrabacher, a former Republican congressman from California, was present at the second meeting where Parnas said DeSantis discussed medical marijuana use. Rohrabacher told Reuters he does not recall the meeting or hearing DeSantis talk about marijuana. “What do I remember from five years ago?”

Parnas says after their second meeting, he told DeSantis that he would try to secure a formal Trump endorsement by promoting DeSantis with Giuliani. Parnas spoke with Giuliani the next day, recommending that he talk with DeSantis and back him, he said. In July 2018, DeSantis publicly expressed support for medical marijuana.

• A Reuters report