Apple's iPhone boss, Mark Papermaster, has left the company in a surprise exit this month, with growing speculation over the reasons for his departure.

Papermaster was Apple's senior executive responsible for engineering on both the iPod and the iPhone. He has been at Apple just under two years. Previously he worked at IBM for 25 years where he was an expert on IBM's Power chips.

Papermaster's departure follows the iPhone 4 'antennagate' PR debacle, with many industry observers suggesting that his exit from Apple may well be closely connected to the mobile reception problems with the iPhone 4.

Fall-out with Jobs

It is unclear whether or not Papermaster has resigned or has been fired. Apple spokesman Steve Dowlings confirmed that Bob Mansfield, senior vice-president of Macintosh hardware engineering, is currently set to assume his responsibilities.

The Wall Street Journal reports that Papermaster and Steve Jobs fell out months ago and that Jobs had lost confidence in the iPhone exec.

The reasons for Papermaster's departure will no doubt become clearer over the coming days. Stay tuned for updates.

Via The New York Times and Wall Street Journal