As the Russian intrigues surrounding Donald Trump and his presidential campaign have continued to pile up, one name has resurfaced at nearly every turn: Paul Manafort. Less than two weeks after it was revealed that United States law-enforcement and intelligence agents reportedly intercepted communications between suspected Kremlin operatives and a number of key Trump associates—including the president’s former campaign chairman—Politico reports that Manafort may also have been subjected to blackmail while he was serving on Trump’s campaign last summer.

A series of hacked, undated communications allegedly from the iPhone of Manafort’s daughter—which Politico reports surfaced a couple of weeks ago on a darknet Web site run by a hacktivist collective—suggest that Ukrainian parliamentarian Serhiy Leshchenko contacted Manafort, claiming to have compromising information about the political operative and Trump. “I need to get in touch with Paul i need to share some important information with him regarding ukraine investigation,” the unidentified sender apparently wrote in one message, using the e-mail address “mail.pravda@icloud.com.” In another, according to Politico, the sender wrote, “I actually have proofs [sic] that he received money,” before warning that if they did not receive a reply, they would pass along the damaging information to the F.B.I., Ukrainian authorities, and the media.

Along with the text messages the sender included a note further detailing the “bulletproof” information they purportedly had on Manafort and Trump. The sender alleged that they had evidence financially linking Manafort to Viktor Yanukovych, a Vladimir Putin ally and the former Ukrainian president. The note also refers to an alleged 2012 meeting between Trump and Serhiy Tulub, whom Politico reports is an associate of Yanukovych, along with an apparent threat of blackmail. “I would like to get your opinion on this and maybe your way to work things out that will persuade me to do otherwise,” the sender wrote, after suggesting they might bring “all the facts and evidence” in their possession to the authorities. (Manafort denied having set up a meeting between Tulub and Trump, in 2012, to Politico and added that he was not working for the New York real-estate mogul at the time. A White House spokesperson declined to comment to the outlet on the whether the meeting took place, but also noted that Manafort, who joined the Trump campaign until early 2016, was not working for Trump at the time of the alleged meeting.)

Politico reports that the e-mail address the sender urges Manafort to contact—Leshchenko@mail.ru—is one that reporters have previously used to reach Leshchenko. The sender’s signature—“Sergii”—is also an “alternative transliteration of Leshchenko’s given name.” In a statement to Politico, Leshchenko denied having sent the text messages to Manafort’s daughter. “I've never written any emails or messages to . . . Manafort or his family. I don't know their contact details,” he told the outlet, adding that he has “nothing to do with” the e-mail address associated with the text messages. In a separate Facebook post, the Ukrainian further denied any involvement in a blackmail scheme, writing that the “correspondence with Manafort's daughter is obviously fake,” according to Politico’s translation.

Manafort, however, confirmed the authenticity of the texts. He also told Politico that he personally received similar texts sent to his phone that also included the e-mail address seemingly associated with Leshchenko. He said he did not reply to the messages, and turned them over to his lawyer. While the screenshots of the text messages allegedly stolen from Manafort’s daughter’s phone do not include date information, Manafort told Politico that they were sent shortly before The New York Times published a report in August alleging that entries in a “secret ledger” obtained by Ukraine’s National Anti-Corruption Bureau revealed Manafort was designated to receive a total of $12.7 million in undisclosed payments over a period of five years from Yanukovych’s pro-Russian political party. Manafort, who resigned from the Trump campaign shortly after the story was published, has continually denied any wrongdoing.