The FBI has arrested the chair of Harvard University’s chemistry department, accusing him of lying about his work for a Chinese university, and charged two others who worked in the Boston area with aiding China’s efforts to steal scientific research, officials announced Tuesday.

“All of the individuals charged today were either directly or indirectly working for the Chinese government at our country’s expense,” said FBI Special Agent in Charge Joseph Bonavolonta. U.S. officials said the activity they uncovered is part of an ambitious, years-long effort by the Chinese government to steal intellectual property and technology to better compete in the global marketplace.

U.S. officials estimate that China’s alleged thefts of trade secrets cost U.S. businesses tens of billions of dollars a year. John Demers, head of the Justice Department’s national security division, said American universities “should take this threat seriously and continue to take actions to confront it, including ensuring transparency in their programs’ funding sources and their professors’ commitments, and having secure physical and Internet security for their sensitive research.”

Charles Lieber, the Harvard professor, lied to Defense Department investigators when they questioned him in April 2018, according to court papers. He claimed in the interview that he had never been asked to participate in China’s research program called the Thousand Talents Plan, designed to attract top-flight academics and experts to work in China, the documents say.

U.S. officials said Lieber signed a contract years earlier to do work for the Wuhan Institute of Technology in China, making as much as $50,000 a month from the school in addition to a living allowance and grant money.

Lieber, 60, was under contract as part of the Thousand Talents Plan from 2012 to 2017, according to a criminal complaint filed against him. As the recipient of federal grant money, Lieber was required to disclose to the government any significant foreign financial conflicts of interest, including payments from foreign entities.

An expert in nanotechnology, Lieber was arrested Tuesday morning by federal agents. His lawyer did not immediately respond to a message seeking comment. Harvard said in a statement that he has been placed on leave.

“The charges brought by the U.S. government against Professor Lieber are extremely serious,” the statement said. “Harvard is cooperating with federal authorities, including the National Institutes of Health, and is conducting its own review of the alleged misconduct.”

Peter Zeidenberg, a lawyer who has represented Chinese Americans accused of espionage, said in an email that the Justice Department “has launched an all-out war on any U.S. scientist associated with the 1000 Talent or other Chinese Talent programs.”

He said that is a major shift in U.S. practice after years of lax scrutiny of the issue.

“The government is now expecting perfect compliance for scientists who received no training on how these forms needed to be filled out and no warnings about the dangers of submitting an inaccurate form,” Zeidenberg said. “Treating these mistakes as felonies is entirely inappropriate.”

Separately, the Justice Department charged Yanqing Ye, a student in Boston University’s departments of physics, chemistry and biomedical engineering, with lying on her visa application and failing to disclose that she was a lieutenant in China’s People’s Liberation Army. FBI agents found evidence that she was carrying out tasks for her military superiors, such as conducting research, assessing U.S. military websites and sending U.S. documents to China, the Justice Department said.

Ye, 29, was charged with visa fraud, making false statements and acting as an agent of a foreign government. She is in China.

The third case announced Tuesday was against Zaosong Zheng, who worked as a cancer researcher at Beth Israel Deaconess Medical Center in Boston from 2018 to 2019. Zheng is accused of trying to smuggle 21 vials of biological research material back to China in a sock in his luggage. When he was stopped at the airport and questioned about the vials, he allegedly told investigators that he wanted to use them to conduct research in China.

Zheng, 30, was arrested last month on charges of smuggling and making false statements.

Zheng’s lawyer, Inga Bernstein, said: “As far as we know and can tell, the charges against our client are entirely unrelated to other prosecutions being pursued by the U.S. attorney’s office. On behalf of our client, we are looking forward to a jury trial so our client can be found not guilty.”

Nick Anderson contributed to this report.