China Business (via The Register) claims that Apple has returned between 5m and 8m iPhones due to quality issues. It’s not known which handsets are affected.

The Register calculates that the total hit to Foxconn could be $1.6bn, but that of course assumes that the numbers are accurate and that nothing can be salvaged from the rejected phones. This is unlikely.

Foxconn posted record profits in the final quarter of 2012 before experiencing a 19% year-on-year drop in the first quarter of this year. More recently, it was reported that Apple had asked Foxconn to take on additional staff to meet production demand for new handsets (assumed to be the 5S and low-cost iPhone).

It could create worries for Apple, however: with numbers that large, it could potentially create stock shortages if the handsets are existing models, or launch delays if they are new ones – though any such issues are likely to be short-lived.