Xi-an Institute of Technology apparently tried to help Foxconn find a new method of cheap labor: unpaid interns.

The Daily Mail reported Foxconn had investigated claims of several students who said they were forced to work overtime during the assembly process of the PlayStation 4 or else they would lose their college credit.

The students, unpaid interns from Xi-an Institute of Technology in China, said they were forced to glue pieces together for their course credit. The media students were also given manual labor instead of work related to their studies.

Other Foxconn interns were forced to peel the plastic off the consoles and place certain stickers on them at the company's Yantai plant. Other intern jobs included inserting the instruction manual into the box as well as shipping and distribution tasks.

Foxconn said its internships promised students a chance at practical experience and training, but began its investigation when a "few instances" of interns working nights and overtime surfaced.

"All participating schools are required to follow specific policies established by Foxconn for this program including assurances that participation is voluntary, interns are free to terminate their internship at any time they choose, and interns are not allowed to take part in overtime work or work night shifts," a Foxconn spokeswoman told the Daily Mail.

Sony did not respond for comment on the matter.

"In the case of recent allegations regarding the Internship Program at our Yantai campus, we have conducted an internal investigation and have determined that there have been a few instances where our policies pertaining to overtime and night shift work were not enforced," the spokeswoman said. "Immediate actions have been taken to bring that campus into full compliance with our code and policies."

Foxconn employs about one million people and produces some of the world's top gadgets like the iPhone, iPad and Amazon Kindle, as well as the Xbox and PlayStation game consoles.

About a year ago, hundreds of workers rioted at the Chengdu plant in China for reasons related to low pay.