State Department officials found “an almost complete lack of cultural activities” for the students sent by Cetusa to the plant, and a “laxness” about their health and safety. The strains of the packing jobs and injuries that resulted were overlooked by the company, officials said.

Students’ complaints were routinely ignored and in some cases were met with “unacceptable threats and intimidation” that their visas could be canceled, officials said. The investigation also raised questions about whether the students had been overcharged by Cetusa for housing, the officials said.

Rick Anaya, the president of Cetusa, which is based in California, did not respond to requests for comment by telephone and e-mail.

Although a nonprofit, Cetusa, which sponsored more than 5,000 students last year, stands to lose at least $5 million in annual fees for the summer program. The company also created businesses providing health insurance to the students. State Department officials are reviewing Cetusa’s participation in three other academic exchanges. Under formal rules, the company could reapply after two years, but a return in that time appeared unlikely.

Several foreign students who worked at the packing plant, now back in their home countries, said they were excited to learn of the impact of their outcry.

“I hope this sends a clear message to other recruiters like Cetusa, that we will not be your captive workers,” said Harika Duygu Ozer, a medical student who spoke via Skype on Wednesday from Istanbul. For many students, their experience last summer in the United States turned into a disturbing immersion in the realities of the American workplace but also an eye-opening lesson in the possibilities of public protest.

Under the summer program, which was started in 1963, about 103,000 foreign university students, using a visa known as J-1, came to this country last year for up to four months to work in mainly unskilled jobs and then to travel. Most come from China and from former Soviet-bloc nations in Eastern Europe, with some from Latin America. The State Department prizes the program as a way to reach young people abroad who may not be able to afford travel to the United States without work here to defray costs.