The U.S. government has urged Nigeria to release an employee of the giant cryptocurrency exchange Binance who was arrested there in February and has faced mounting medical problems in prison, according to two senior State Department officials.
The detention of Tigran Gambaryan, a former U.S. law enforcement officer, has become a significant factor in the diplomatic relationship between the United States and Nigeria, said the officials, who requested anonymity to discuss a diplomatic matter.
Secretary of State Antony J. Blinken raised the issue with his Nigerian counterpart in May, the officials said. Other U.S. diplomats, including the ambassador to Nigeria, have called for Mr. Gambaryan’s release in private conversations with Nigeria’s president, finance minister, attorney general and trade minister, according to the officials.
The U.S. diplomats have argued that Mr. Gambaryan, 40, should be freed on humanitarian grounds, after he suffered from malaria and problems stemming from a herniated disk, the officials said. His family has said he hasn’t received adequate medical treatment, causing his health to worsen rapidly.
Mr. Gambaryan traveled to Nigeria in February to hold meetings with local officials about Binance’s business dealings in the country. Nigerian authorities said Binance, the world’s largest cryptocurrency exchange, had harmed the nation’s economy by allowing users to transfer funds out of the local currency, the naira, causing it to collapse.
Nigerian prosecutors charged Mr. Gambaryan and Binance itself with tax evasion and money laundering. The tax charges against Mr. Gambaryan were dropped, but the others are still in place. Binance denied the claims and argued that Mr. Gambaryan was a midlevel employee who should not be held responsible for the company’s actions.
A representative for Nigeria’s federal government said on Thursday that Mr. Gambaryan had access to medical care from qualified doctors, and that “the courtroom is the correct forum to assess the merits of any prosecution.” Bayo Onanuga, an adviser to Nigeria’s president, Bola Tinubu, said the U.S. ambassador, Richard M. Mills Jr., met this month with the president’s chief of staff, the national security adviser and other officials.
“Talks are ongoing,” Mr. Onanuga said. “Government will do all it can within the law, and also bearing in mind Gambaryan’s humanitarian rights.”
Nigeria made its allegations against Binance shortly after the company agreed to a $4.3 billion settlement with a group of U.S. agencies that had accused it of facilitating money laundering. In November, Binance’s founder, Changpeng Zhao, stepped down as chief executive and pleaded guilty to a money-laundering violation. He was sentenced to four months in prison.
Mr. Gambaryan, a former criminal investigator for the Treasury Department, was one of the first U.S. law enforcement officers to take a serious interest in crypto cases. He joined Binance in 2021 to help run its compliance operation and meet with law enforcement officers around the world who were investigating crypto-based crimes.
He was arrested during one of those meetings. After a few weeks, Mr. Gambaryan was transferred to Kuje prison in Abuja, a notorious facility that has also housed members of the Islamic State and Boko Haram.
At Kuje, Mr. Gambaryan has struggled with medical issues, according to his family. He has suffered from malaria and pneumonia and is now largely bedridden from the effects of a herniated disk, a decade-old condition that he was able to manage before his arrest.
In court this month, Mr. Gambaryan hobbled on a single crutch and pleaded with a guard to let him use a wheelchair. Last month, an American spine specialist said Mr. Gambaryan might require surgery and could face long-term neurological damage if he didn’t receive adequate treatment, according to medical documents reviewed by The New York Times.
Since June, the State Department has privately urged the Nigerian government to release Mr. Gambaryan, saying he has not received proper medical care, the senior officials said. But his supporters have called on the United States to do more.
Robert S. Litt, a lawyer for Mr. Gambaryan, said the charges were “trumped-up.”
“Nigerian authorities know he is wholly innocent,” Mr. Litt said.
Mr. Litt has urged the State Department to invoke a four-year-old law, the Levinson Act, to designate Mr. Gambaryan as “wrongfully detained.” That would be a major escalation, and could open the door to sanctions against individual Nigerian officials, or other punitive actions.
The State Department has not ruled out such a move, the officials said, and is monitoring the case for “indicators of wrongfulness.” But the U.S. government still has some faith in Nigeria’s court system, one of the officials said.
A person close to Nigeria’s president said local officials felt that the United States was interfering in the country’s judicial process. Nigerian officials do not see a humanitarian issue, said the person, who was not authorized to speak publicly.
Nigeria has long been a close American ally. The United States works with officials there to combat terrorist financing and violent extremism, according to a fact sheet on the State Department’s website. Nigeria is also the United States’ second-largest trading partner in Africa and received $1.2 billion in U.S. aid in the 2022 fiscal year.
High-level Nigerian officials are expected to visit New York this month for the United Nations General Assembly. In an interview this week, Mr. Gambaryan’s wife, Yuki, said she “would be very upset if the U.S. government welcomes Nigerian delegates with open arms.”
Ismail Auwal contributed reporting from Abuja, Nigeria.
