A Libyan national who says he escaped summary execution by Russian Wagner Group mercenaries filed a lawsuit in a court in Washington on Tuesday naming as defendant the group's founder - Yevgeniy Prigozhin.

The suit alleges that Wagner fighters stationed in Libya murdered three members of a local family in 2019 after detaining them without explanation. The plaintiff in the case, Libyan national Mohammed Aboujaylah Ali Anbees, survived. According to an English-language account shared with the court, the details of which have not been verified independently, Anbees said he is alive because he played dead after two Russian mercenaries killed his father, brother and brother-in-law, in what appeared to be haphazard, drunken fire with AK-47 rifles.

"Anbees laid on the ground in the pools of blood of his family members" until the Wagner soldiers drove away, leaving him and another wounded family member for dead, the account states.

The civil case, enabled by a federal law that targets gross violations of human rights by individuals, is an attempt to seek accountability from Prigozhin, whose failed mutiny in Russia last month threw the country into turmoil before ending with his exile to Belarus. The lawsuit also names Khalifa Hifter, the Libyan warlord who brought the mercenary group to Libya in 2018. The law does not require the parties in the case to be U.S. citizens.

A request for comment, sent to an email account associated with Wagner and Prigozhin, did not receive a response.

Tens of thousands of Wagner mercenaries, many of them convicts freed Russian prisons to fight for the group, played a crucial role in Russia's war in Ukraine, particularly in the battle over the ruined city of Bakhmut, before Prigozhin withdrew them amid clashes with top Russian military figures in the run-up to his abortive mutiny. But Wagner fighters for hire also have fought all over the world, especially in Africa in the Middle East.

While it remains unclear what practical impact Anbees's lawsuit could have on Prigozhin, who has no known U.S. assets that could be seized as damages. The governments of Russia and Belarus are vanishingly unlikely to cooperate with the court. But Anbees's account could draw attention to accusations of human rights violations by the Wagner Group that have piled up over years, many of them in the context of murky conflicts in which the group appears to have acted with free rein and few repercussions.

According to the account provided to the court, on the afternoon of Sept. 23, 2019, Anbees and several male family members were driving near their home in Espiaa, a village near Tripoli, when they were stopped by armed men, who later followed them to their home and detained them.

The armed men took them in a refrigerated truck commandeered from a juice factory, driving for hours away from the family home. The soldiers, who were drinking alcohol, did not respond to questions in Arabic, although one soldier demanded to know in broken English if the Libyan family had links to the extremist group known as the Islamic State.

The account says that the men could be identified as Wagner mercenaries, as they had "blue eyes," clear military training and drove a "unique model of vehicle." After the shootings occurred and the apparent Wagner mercenaries left, Anbees aided one of his brothers who survived, despite being shot in the leg, in escaping. Anbees remains in Libya.

Human rights advocates hope the suit, filed on Tuesday in U.S. District Court in Washington, could be the beginning of broader efforts to probe the mercenary network's lucrative involvement in conflicts. Wagner's actions in Libya took place years before Russia's invasion of Ukraine led Prigozhin to publicly acknowledge his ties to the group.

Kip Hale, a lawyer specializing in atrocity crimes accountability and who served as investigation team leader of the United Nations' Independent Fact-Finding Mission on Libya, said airing the allegations in a court would allow facts to be vetted and established. It could serve as a catalyst for later accountability, he said.

"That's not to say that Wagner's leaders and all of their fighters are going to be dragged into court," Hale said. "But it puts pressure on them, which is very important when dealing with Russians" who are well-known for trafficking in disinformation.

The lawsuit could also add to the legal pressure on Hifter, a former general and CIA asset who also has U.S. citizenship and has used Wagner to help wage war against a U.N.-backed Libyan government for control of the country for years. The group that is helping the plaintiff bring its case against Prigozhin and Hifter, the Libyan American Alliance, has brought several lawsuits against Prigozhin for his alleged involvement in torture and extrajudicial killings.

The cases were brought under the Torture Victim Protection Act, a 1991 law that requires a plaintiff to show that the person has exhausted local legal remedies.

"No member of the Wagner Group in Libya should feel safe or exempt from facing justice," said Omar Tabuni, the advocacy director for the Libyan American Alliance. "The Libyan families who have endured and continue to suffer from these crimes deserve their day in court."

Cases were previously filed against Hifter in the Eastern District of Virginia, in the state where the Libyan lived for years and where he had substantial property holdings. One of the cases is pending, with Hifter last year invoking state secrets to refuse to answer some questions during a deposition and his attorneys calling the case an attempt to cull "political fodder."

Before filing Tuesday's lawsuit, Anbees had given an account of the deaths of his family members to Arabic-language media outlets. He also spoke on the condition of anonymity to a U.N.-backed fact-finding mission team that visited Libya this year and published a report finding "reasonable grounds" to believe that Wagner fighters involved in the case "committed war crimes of murder, torture and cruel treatment."

Prigozhin's and Wanger's fortunes have changed dramatically since 2019: The onetime hot dog seller and state-catering-contract mogul who orchestrated disinformation and mercenary networks from the shadows became, in short order, a fixture on the front lines of the war in Ukraine, a loose cannon known for criticism of the Russian war effort with which few other people could get away and eventually open mutiny that ended in his exile to Belarus.

The future of Wagner's international operations remains unclear. U.S. intelligence documents leaked this year indicated that Wagner conducted operations in 13 African nations, although the scale of its actions varied widely. In April, Anas El Gomati, the director of the Tripoli-based Sadeq Institute think tank, told The Washington Post that the Wagner Group was "probably the most destabilizing actor now operating in Libya."

Wagner fighters had come to the aid of Hifter's self-described Libyan National Army, according to numerous outside assessments. Experts have described the conflict in Libya as a proxy war, with the Russian state backing Hifter, who also has been allied with Egypt, Saudi Arabia and the United Arab Emirates. Most European nations, as well as Turkey and Qatar, have backed the Tripoli-based government recognized by the United Nations.

Although most fighting ended in 2020, it is only a fragile peace. The Libyan National Army continues to hold much of easternmost Libya. In January, CIA Director William J. Burns made a rare visit to the country and asked leaders to expel Russian personnel and to hold long-delayed national elections.

A report submitted to Britain's parliamentary foreign affairs committee last year suggested that Wagner was able to operate in eastern Libya with "relative impunity" and that since 2020, the group had operated "under Moscow's payroll serving Russian objectives."

The Washington Post's Salvador Rizzo contributed to this report.