"You know he has killed people in Ukraine? Knowingly," Andrea Manafort allegedly wrote of her father in March 2015 in an angry series of texts to her sister, Jessica, about her father's personal and professional life, CNN reported.
"Remember when there were all those deaths taking place. A while back. About a year ago. Revolts and what not," reads another text in reference to the bloodshed in Kyiv.
"Do you know whose strategy that was to cause that, to send those people out and get them slaughtered."
"He has no moral or legal compass," Andrea allegedly wrote about her father earlier as part of the same conversation.
The messages were obtained from a hacker website that in February posted four years' worth of texts, consisting of 300,000 messages, apparently taken from Andrea Manafort's iPhone.
Paul Manafort currently faces an FBI investigation over millions of dollars' worth of payments he allegedly received while working as a political strategist for Ukraine's Russia-backed president, Viktor Yanukovych. Manafort has denied receiving the undeclared cash payments.
Protesters descended on Kyiv's central square in a peaceful protest in the winter of 2013 when Yanukovych unexpectedly backed out of a trade deal with the European Union under pressure from the Kremlin. Close to 100 people died in the shootings in the weeks before Yanukovych fled in February 2014.
Ukrainian authorities say Yanukovych created conditions that allowed security forces to kill the pro-Western protesters in Kyiv, but so far have not been able to charge him because he is in Russia.
Manafort has not been linked to the shootings.
Read alsoManafort's Ukrainian associate under FBI scrutiny - mediaAsked by CNN to comment, Manafort said via text message: "Comment on what. There is nothing."
Manafort would not confirm whether the texts were genuine, but in a Politico story last month on the texts, he indicated that some of them were.
The texts suggest that Manafort and his daughter were together in Florida on the day of the worst violence in Kyiv on February 20, when close to 50 people died.
Thursday, the human rights lawyer, Eugenia Zakrevska, filed a motion in Kyiv requesting that prosecutors verify the contents of the text message dump and take measures to compel U.S. authorities to question Manafort.
"I call on Mr. Manafort to clarify the allegations contained in the text messages and to contact us with any information he may have on those events," Zakrevska told CNN.
Zakrevska and a special prosecution unit have been working together on several concurrent cases looking into the violence in and around Kyiv's Independence Square.
Zakrevska said all of the killings would have already taken place by the time Manafort met his daughter the evening of the 20th if the texts' timestamps are accurate, and she thought it was unlikely that Andrea actually witnessed Paul Manafort personally directing Kyiv police forces.
"But this doesn't rule out Manafort's influence on Yanukovych's actions and decisions during that period," Zakrevska said.
Serhiy Gorbatyuk, Ukraine's prosecutor for special investigations, confirmed to CNN that his office received Zakrevska's motion and said the text messages would be investigated and potentially entered into evidence. "We will check thoroughly to verify if they are real or not."
Asked by CNN about the prospect of an investigation by the general prosecutors' office, Manafort replied: "Total BS on GP (general prosecutor)."
Read alsoPaul Manafort: Ukraine gov't said Party of Regions' "black accounts" was falsified documentManafort began working for Yanukovych in 2004 and grew to be an influential figure in Ukraine who had the ear of the President. After Yanukovych was ousted and pro-Western forces took the reins, Manafort stayed on in the country to help rebrand Yanukovych's Party of Regions as "Opposition Bloc."
Manafort joined the Trump campaign in March 2016 and was pushed out in August.
The text messages, if genuine, shed light both on the last days of the Yanukovych regime in Ukraine and a turbulent period in the Trump campaign last summer, when Trump shook up his team's leadership structure.
They also cover the time period when Russia, according to U.S. intelligence agencies, may have been conducting hacks into email accounts associated with the Democratic Party.
In the same 2015 conversation with her sister, Andrea allegedly suggests to Jessica that their father used covert methods to send messages to Ukraine.
"I was there when it happened. I saw him on his shady email," she allegedly wrote. "They don't write emails. They log on and write in the drafts. So it's never transmitted over any servers."
In another alleged exchange with Jessica, in June 2016, Andrea plays down her father's involvement in the hacks of the Democratic Party emails.
"Pretty crazy about all the email hacking huh?" the texts read. "Dad must be over the moon."
"Oh I saw." is the reply. "The Russians."
"Well, it wasn't dad's doing. It was hackers," Andrea allegedly writes back. "No clue who the hackers were. FBI is looking into it."