The investigation was prompted by a report in the London newspaper Mail on Sunday, which insinuated that workers at the plant -- E3 --were being treated unfairly and forced to operate under sweatshop-like conditions.
"Apple has begun a thorough audit of the manufacturing plant operated by Foxconn in Longhua, China," said Apple spokesman Steve Dowling.
The audit will focus on "employee working and living conditions, interviews of employees and managers, compliance with overtime and wage regulations, and other areas as necessary to insure adherence to Apple's supplier code of conduct," Dowling added.
Monday was the first time Apple disclosed the details of the investigation, which it committed to last week.
For its part, Foxconn has denied any wrongdoing.
A spokesman for the company on Monday said there were "huge discrepancies" between the truth and the allegations in the Mail's report, which he called "vicious attack" on Foxconn.
The Taiwanese computer and electronics manufacturer maintains that its "employment practices are completely in accordance with the requirements of Shenzhen labor supervision departments."