Reporting Highlights

Pay for Play: A naval firm based in Hawaii directed campaign funds to South Carolina politicians and secured federal contracts in the state.
Big Players: Lindsey Graham and James Clyburn, influential leaders in South Carolina, directed federal resources toward Navatek.
Questionable Merit: The value of the contracts appeared limited. "The whole thing is a grand lie," said the former CEO.

These highlights were written by the reporters and editors who worked on this story.

On March 3, 2020, Sen. Lindsey Graham entered a private dining area at Charlie Palmer Steak in Washington, D.C. Graham's schedule carried a high cost. He sat down with two executives and a lobbyist from a Hawaiian naval defense contractor named Navatek. He had insisted they pledge $40,000 in campaign contributions for a 45-minute session.

Navatek's CEO, Martin Kao, believed that brief window would suffice.

"Shoot all he has to really do is stop by and say 'yes,'" Kao wrote to a Navatek lobbyist and another executive the prior day, in an email reviewed by ProPublica. "That should only take a minute and he's on his way. We don't need to pretend we give a shit about each other."

During the meal, Graham ate sparingly and spoke extensively. Yet Kao received the "yes" he sought: Graham consented to direct a $10 million government contract to Navatek in his home state of South Carolina, Kao later told the FBI. In return, he stated, Graham requested a commitment of $100,000 total for his reelection bid.

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In early 2025, the FBI launched a broad inquiry into bribery on Capitol Hill, centering on Graham's steakhouse meeting. Kao admitted to federal agents that his company's approach relied on bribing officials for government work, and that the research Navatek supplied to the government was frequently of little value.

The arrangement included some of the most influential members of Congress, he indicated - from both parties. In South Carolina, Kao informed agents, Navatek arranged campaign cash-for-contracts agreements not only with Graham, but also with the state's leading Democrat, Rep. James Clyburn, and another key Republican, Rep. Joe Wilson.

Kao explained to agents that Graham left little doubt: "This is how much I want, and how much I am going to give you," Kao recalled Graham stating, per notes taken by one agent during their discussion in late 2024.

Kao's statements would point to a wide criminal bribery operation if established in court - a difficult task, given recent Supreme Court decisions that have complicated corruption prosecutions. Kao himself created another obstacle. He faced prison time for fraud and campaign finance breaches and was cooperating with the FBI to seek a lighter sentence.

Still, the FBI agents who heard Kao's account - two seasoned anti-corruption investigators - noted that much of it matched a large set of records they had obtained from Navatek. They continued the work. The FBI formally listed two former Navatek executives who had collaborated with Kao as targets in a bribery inquiry. The agency did not label Graham, Clyburn and Wilson in that manner, but the agents were examining their dealings with Kao. The agents noted to their supervisors that the lawmakers might become targets later, according to records examined by ProPublica.

The specifics of this investigation have not been shared before.

President Donald Trump returned to the White House and quickly dismantled the specialized FBI and Department of Justice units focused on public corruption - a move seen as retaliation for prior probes into him. The two experienced agents on the case were caught in the staff reductions, and the career prosecutor supporting them resigned after Trump appointees barred the DOJ's anti-corruption section from starting new matters. Today, no one remains to examine Kao's serious claims, as the Trump administration has dropped any effort to pursue public corruption cases. The matter is closed.

ProPublica has uncovered the investigation through review of thousands of pages of legal files, internal company emails, evidence the FBI used to check Kao's statements and dozens of interviews with individuals familiar with Navatek's operations, including a witness to Graham and Kao's private steakhouse dinner.

This story forms part of a series based on our reporting. Last month, ProPublica reported that the FBI had examined the actions of Maine Sen. Susan Collins, who directed millions in government funding to Navatek while Kao provided her improper campaign donations. Collins denied any misconduct and described Kao as a "convicted liar."

Kao is the sole individual involved to serve prison time. He pleaded guilty to illegal campaign donations and a loan fraud scheme in 2022. In 2025, he received a sentence of 87 months in prison.

Graham passed away at 71 earlier this year. His sister, Darline Graham, who was selected to complete his term, kept most of his senior staff, including those who handled Navatek matters. She also assumed some of his committee roles, including appropriations. Darline Graham is seeking a full term in office this November.

Clyburn, 86, ranks among the most influential Democrats in Washington. He is widely recognized for helping Joe Biden in the 2020 Democratic presidential primary. Wilson continues to hold sway over national defense spending from his senior position on the Armed Services Committee.

"Whatever a donor may think or say, a donation would never cause Congressman Clyburn to increase his support for the donor's request," Jami LaRue, Clyburn's communications director, wrote in response to detailed questions. "The Congressman has always striven to assist the University of South Carolina and all of the colleges and universities in his district when called upon to further their important missions. The crimes and lies of an imprisoned fraudster will not cause the Congressman to waver in his support for these fine institutions."

David Snider, Wilson's communications director, did not respond to a detailed list of questions sent by ProPublica. "Congressman Wilson does and has always abided by campaign donation regulations set forth by the Federal Election Commission," Snider said in an email.

In an emailed statement, Taylor Reidy, who served as Lindsey Graham's communications director and now holds the same role for his sister, wrote that "any allegations of quid-pro-quo behavior or wrongdoing by the late Senator Lindsey Graham or his staff are simply false." She said the claims were the "ravings of a convicted felon" and that her office was never contacted by the FBI about the issue. After Kao's arrest, they returned his donations, she added.

The two executives who were targets of the FBI investigation, Duke Hartman and Joshua Knight, were never charged. Hartman, the other executive at the dinner meeting with Graham, is now the CEO of a new naval research company called Integer Technologies that he co-founded with Knight after Kao's arrest. Integer was recently noted as one of the fastest-growing government contractors in the country. It also became the ultimate recipient of the Graham dinner meeting, securing the contract Graham allegedly agreed to support that night.

Hartman and Knight did not respond to detailed requests for comment.

"[It's] corruption at its best," Kao wrote to ProPublica from federal detention in South Dakota, before ending contact. "But I am the only one rotting in prison."

Small Company, Big Ambitions

Kao's dinner with Graham formed part of his ambitious effort to turn Navatek into a major defense contractor.

He had taken the CEO role at a challenging time for the company. Founded in Hawaii in the 1970s, the company had prospered from ties to the state's senior senator, Daniel Inouye. When Kao assumed ownership in 2019, several years had passed since Inouye's death, and Navatek needed a new advocate in Washington.

At times, Kao did not appear suited for the task. He had begun as the company's CFO and showed little interest in its technology. He told exaggerated stories about his personal background. Former employees said he shared accounts of selling newspapers for members of the Bloods and Crips street gangs as a youth. In a deposition, Kao later admitted that was not accurate.

Yet what he lacked in technical expertise he compensated with drive. Once, Kao led a company meeting using a map of the U.S. marked with future Navatek offices as his background, a former employee recalled. "He would talk about how we're a $10 million company, and in the next three years, we're going to be a billion-dollar company," said a former engineer. "He was an absolute megalomaniac."

Kao developed a strategy to grow Navatek's footprint nationwide, building new connections in Congress. He engaged politicians through what he termed "the method," as ProPublica described in September.

Navatek would establish an office in the state or district of a powerful member of Congress and team with a local university to create a proposal for federally funded research. Then, supported by a well-connected lobbyist and the appearance of credibility from its university link, Navatek would seek federal research funding from the member.

Kao told the FBI he would finalize agreements in small, in-person meetings with the members or their trusted staff. Navatek - through executives, family members and lobbyists - would provide substantial campaign donations. In exchange, the member would insert specific language into the defense budget to support the company's projects.

That legislative language would not name the company. But it would detail specific work that Navatek was already preparing to perform behind the scenes, positioning it as the sole logical choice for the eventual government contract. The lawmakers' staff would also communicate privately with the Navy after the bill passed to ensure contracting offices directed the funds to Navatek, emails reviewed by ProPublica show - even though the contracts were supposed to be competitive.

Kao "wanted to build a company as big as he could as fast as he could," a former executive later testified in court. For a period, he succeeded. Under Kao, Navatek moved from needing to "rebuild," as the executive put it, to securing $40.7 million in new government contracts in 2020.

Hartman, the other Navatek executive who attended the dinner with Graham, oversaw relations with Congress while monitoring the millions of dollars the company had sought in research funds. He tracked the company's progress with dozens of color-coded spreadsheets. "If anyone knows the impropriety of the business model, it's him," Kao told the FBI, referring to Hartman.

Later, these spreadsheets gave the FBI a clear view of which congressional offices worked most closely with Navatek. In the sections on South Carolina, Navatek marked Graham as a "key supporter."

The company focused mainly on lawmakers from smaller states who served on appropriations committees, like Collins, Kao explained to the FBI, because they controlled large portions of the budget while having fewer "constituents to 'feed.'"

The senior senator from South Carolina was another strong target. "You can get access to Lindsey Graham," Eric Schiff, a former Navatek executive, said in an interview.

Kao, Hartman and other Navatek executives reached out to the offices of Graham, Clyburn and Wilson - all influential members of the South Carolina delegation - at the start of 2019. The company had partnered with the University of South Carolina on a joint research project, and together they requested the lawmakers secure $9.5 million to support the work. If successful, Navatek planned to seek renewed funding from Congress for two additional years as well as approval for two more projects, internal company records show, for a potential total of up to $90 million in South Carolina alone.