A company in which President Trump’s brother has a financial stake received a $33 million contract from the U.S. Marshals Service earlier this year, an award that has drawn protests from two other bidders, one of which has filed a complaint alleging possible favoritism in the bidding process.

The lucrative government contract, to provide security for federal courthouses and cellblocks, went to CertiPath, a Reston, Va.-based company that since 2013 has been owned in part by a firm linked to Robert S. Trump, the president’s younger brother.

After the contract was awarded, an anonymous rival bidder filed a complaint with the Justice Department’s office of the inspector general alleging that CertiPath had failed to disclose that “one of the President’s closest living relatives stood to benefit financially from the transaction,” according to a copy of the July 22 complaint letter obtained by The Washington Post.

“The circumstances of this contract award, and what appear to be CertiPath’s efforts to obscure Mr. Robert Trump’s financial interest in the company even as it trades on the Trump name, present the appearance of preferential treatment for those who are close to the President,” said the complaint, which was sent by the Washington law firm Venable on behalf of the client.

Dismas N. Locaria, a Venable lawyer who signed the complaint letter, declined to disclose the name of his client.

A phone message left for Robert Trump through Trump Management, where he is a senior executive, was not returned.

CertiPath’s president and founder, Jeff Nigriny, said in a statement that Robert Trump “is one investor in an entity which holds a minority interest in Certipath” and that “he is exclusively a passive investor, has no management role whatsoever, is not an officer or director and his name has never been used or mentioned by Certipath in any solicitation for a government contract, whether state or federal.”

Nigriny said that the company is unaware of the complaint filed with the Justice Department’s inspector general.

The company specializes in digital security and verifying online identities.

“Certipath has never used the Trump name in any way, and to do so would be completely inconsistent with our business practices and ethics,” Nigriny added.

Though the contract has been awarded, no money has been paid out. That is because a second company, NMR Consulting, of Chantilly, Va., also filed a protest of the bid with the Government Accountability Office, on July 1.

That bid protest has led to a “stop work order” on the contract, said Drew Wade, a spokesman for the U.S. Marshals Service.

“There’s no money being spent with CertiPath until this issue is resolved,” Wade said.

Wade added that the Marshals Service had no knowledge of the allegations that a member of the president’s family has a financial interest in CertiPath or that a complaint has been made to the inspector general.

The NMR complaint is about a separate issue and “has nothing to do with the president or his relationships,” Wade said.

NMR did not respond to calls and emails seeking comment.

The Justice Department inspector general has not initiated a review of the matter, according to a public listing of that official’s reviews regarding the Marshals Service. A spokeswoman for the inspector general declined to comment further.

The White House did not respond to requests for comment.

Since Trump took office, CertiPath has been paid more than $6 million in government contracts, federal data show.

Once regularly spotted in New York society circles, Robert Trump has spent his recent years largely out of the limelight.

He followed Donald Trump into the family real estate business in New York and held senior positions in the Trump Organization. In the 1980s, he served as an executive vice president at the company and was involved in the Trump Organization’s casino operations in Atlantic City.

One recent book about Trump’s litigious history cites an anecdote about Robert Trump enduring Donald Trump’s wrath in a meeting with bankers from Bear Stearns about the Trump Taj Mahal casino.

After Robert Trump made a comment that Donald Trump didn’t like, “Trump stood up and pointed his finger near Robert’s face, angrily saying, ‘You talk when I tell you to talk!’ ” according to the book by James D. Zirin titled “Plaintiff in Chief: A portrait of Donald Trump in 3500 lawsuits.”

Robert Trump has been a steady donor to Republican candidates and state committees over the years, his contributions including a $100,000 donation to the “Trump Victory” political action committee in 2016, according to Federal Election Commission data.

“I support Donald one thousand percent,” he told the New York Post that year.

Robert Trump, who reportedly lives in New York’s Dutchess County, is the president of Trump Management, a company that is listed on President Trump’s financial disclosure form.

Through this company, the two brothers appear to have a financial relationship: The company is 25 percent owned by the “Donald J. Trump Revocable Trust,” a trust fund of the president’s assets from which Trump can withdraw money from at any time. The other 75 percent of Trump Management is owned by “Trump Family Members,” according to the president’s financial disclosure form.

Robert Trump has also invested in other companies outside of real estate; he is listed as a board member of ZeniMax Media, a video game maker based in Rockville, Md.

Robert Trump’s stake in CertiPath is through SHiRT LLC, an investment partnership including the younger Trump and CertiPath’s chief executive, Shawn R. Hughes. On the CertiPath website, Hughes’s biography mentions that he is the managing partner of SHiRT LLC. It does not indicate Robert Trump’s percentage of ownership.

In 2013, CertiPath was acquired by two entities; one of them was SHiRT LLC, according to a CertiPath news release from October of that year.

Since then, CertiPath has been paid at least $13 million in U.S. government contracts, according to an analysis of data from the Federal Procurement Data System.

But the contract announced on June 25 by CertiPath appears to be the company’s biggest yet: a “highly-coveted contract,” as the company described it in its announcement at the time, to upgrade and manage “physical access control systems” for the Marshals Service including at judges chambers, courtrooms, cellblocks and firing ranges.

“Our decade-long strategy is being validated,” Nigriny said in a statement at the time.

But the award was quickly challenged by other bidders.

Locaria, the Venable lawyer, said that he has made follow-up calls to the inspector general’s office since he sent the letter in July but has yet to receive a response. He said his client’s motivation was “shining a light on whether this was appropriate.”

Beyond the potential conflict of interest, the complaint letter also alleges that on the basis of CertiPath’s experience, the company should not have won the contract.

“CertiPath, which primarily provides information technology products related to digital identification, appears to lack the basic program management skills and experience required to provide the physical security” for these Marshals Service needs, the letter says.

Nigriny disputed that assessment and said CertiPath’s “technical abilities and operational history are, in our opinion, more than adequate to perform under the contract in an exemplary manner.”