Tech titan Apple has reported marked improvements on working environments of employees hired by the company's mostly Asian contractors to assemble its bestselling electronic devices.

The California firm, however, conceded too that labor infractions still exists as audits conducted by Apple unearthed verifiable allegations of overstretched working hours endured by Apple gadget assemblers.

And many of these workers, the new Apple Supplier Responsibility report issued Friday last week said, were also duped into working with pays not commensurate to the amount of work-hours they logged in.

Apple revealed that only 38 percent of its contractors followed the American company's regulation that workers need only to complete maximum of 60 working hours each week, with the benefit of at least one full day of vacation each week.

In the process of addressing allegations that Apple suppliers regularly withheld full payment to workers, Apple also discovered that many workers employed by its suppliers were made to fork out processing fees to land job positions on factories where Apple products are manufactured.

Such practices, Apple stressed, were not in any way sanctioned by the company.

Upon discovery of the scam, which first surfaced in 2008, Apple ordered its erring suppliers to re-compensate affected employees, resulting to total payments of over $3.3 million as of the last accounting.

Close to $7 million worth of reimbursements has been issued since Apple cracked down on the employee-hiring system, the report, the coverage of which has been expanded by over 80 percent since 2010, said.

"Apple is the only company in the electronics industry that mandates reimbursement of excessive recruitment fees," Apple said.

The company added that audits regularly conducted on its vast supply chain had successfully erased the incidence of child labor on facilities where Apple smartphones and tablet computers were being put together.

"And we will continue regular audits and go even deeper into our supply chain to ensure that there are no underage workers at any Apple supplier," Apple vowed.

In a separate statement, Apple said that it hopes to achieve more transparency on how its factories operate by allowing a third-party monitoring from Washington-based Fair Labor Association (FLA).

The labor group, according to Apple senior vice president of operations Jeff Williams, will be given enough access to specific Apple factories, where they can conduct probes and issue reports.

"With the benefit of the FLA's experience and expertise, we will continue to drive improvements for workers and provide even greater transparency into our supply chain," Williams was reported by Agence France Presse (AFP) as saying on Monday.

A number of labor advocates, however, were critical of FLA's conduct of operations, a check on its Wikipedia entry yielded, and accused the outfit of maintaining questionable codes to properly address labor issues and accepting funding from firms it covers for scrutiny.