Keeping up with its high measures of standards, Apple has been rumored to have returned a batch of an astounding 8 million iPhone devices to Foxconn, as it allegedly wasn’t on par with the Fruit giant’s quality requirements.

This citation has been made today by The Register, which pointed to a report published by China Business. According to the report, the whistleblower was an anonymous Foxconn employee, who revealed that around 5-8 million iPhone units were sent by Apple, “due to appearance of substandard or dysfunctional problems.”

If this report is true, then it’s a huge setback for both the companies, especially Foxconn. With an estimated manufacturing cost around $200 per handset, the iPhone assembler would face a damage of nearly $1 billion, and it would it would leave Apple facing disturbance in iPhone supply.

The report doesn’t mention how many of those allegedly defective iPhones consisted of iPhone 4, 4S or 5. Keeping up with quality control with the introduction of iPhone 5 have been a daunting challenge for Foxconn workers. At one point Foxconn even admitted that iPhone 5 was the most difficult device to assemble. With Foxconn already facing problems in manufacturing iPhone 5S, if today’s setback turns out to be true, than the manufacturing of iPhone 5S is likely to face yet another delay.