Apple has reportedly commenced production of the iPhone 5S following reports that its main Chinese manufacturing partner, Foxconn, beefed up its workforce by tens of thousands, signalling too that release date of the date is imminent.

Reports from CNET indicate that large-scale hiring of local assemblers is ongoing in Foxconn's Zhengzhou production complex, which is located in the Chinese province of Henan.

The mass recruitment will ramp up Foxconn's current headcount of workers, which the report said now stands at 210,000. The ideal target appears to be at least 300,000, which is the same level that Hon Hai Precision had set last year when the iPhone 5 was being manufactured.

The Taiwan-based Hon Hai owns and operates the numerous Foxconn production facilities situated in China.

The jump in the number of workers in Zhengzhou alone signals that volume production of the iPhone 5S has already started, Apple Insider said in a report.

The same report hinted too that as an 'S Edition', the iPhone 5 replacement is essentially of the same look but with upgraded and more powerful components inside. It was also suggested that the fresh recruits will be tasked to put together an iOS handset that is wrapped in a combo shell material of anodised aluminium and carbon fibre.

The final iPhone 5S build is thought to be 40 per cent lighter from the 2012 version and will sport a border-free front face design, basing on various reports from analysts.

Citing a report from China Business News, CNET also noted that there were speculations Apple is building the iPhone 6 this year instead of the 5S. The former is seen the actual upgrade from iPhone 5, bearing a new body design and more powerful specs.

"This appears to be guesswork, as there is no indication of a model number confirmation from Foxconn," the report said.

With the iPhone 5S production activities seemingly in high gear, reports that its release date is on September gain further traction. Likewise, analysts are convinced Apple will debut the cheaper iPhone Lite with its 2013 flagship.