NEW YORK - It sounded like the perfect summer job.
Students from China, Africa and eastern Europe would work in a Hershey's chocolate plant before using their earnings to travel the US and learn English.
"We have all seen Charlie's chocolate factory," said one student, 19-year-old Harika Duygu Ozer. Another said: "I thought we would see America like in movies."
The factory, in Palmyra, Pennsylvania, did not live up to Roald Dahl's thrilling world of chocolate waterfalls and infinite treats, however.
The 400 students, who each paid up to $US5940 ($5700) to join the State department's cultural exchange scheme, claimed they were forced to become "captive workers".
Shifts, often at night, consisted of lifting dozens of heavy boxes, trying to control fast-moving production lines, they said.
"They don't care if you are small, you don't have the power, you didn't eat - they just care about their production," one of the students said.
A spokesman for the National Guestworker Alliance, which is backing the group, said: "They were warned to stop complaining or they would be kicked out."
The students walked out last week in protest at their conditions and pay, which after deductions and rent charges allegedly amounted to between $US40 and $US140 for 40 hours of work per week. They marched with dozens of supporters through Hershey itself.
Hershey said the plant was run by Exel, a logistics company. Exel said temporary workers were overseen by a third company, and that it had been told to stop hiring students from the scheme. It said students were informed of likely working conditions.