The iPhone first released in 2007 was based on a personal digital assistant units produced by Sony in the prior years, according to a new court filing by Samsung in reply to Apple's allegations that Samsung's Galaxy smartphones designs were made to look and feel like the million-selling Apple mobile phone.

"Apple itself originally made clear that it had taken its iPhone inspiration - in part at least - from ideas out of Sony's labs," Samsung was quoted by Slash Gear in a court document that the South Korean firm lodged before the U.S. District Court presided over by Judge Lucy Koh.

The filing was in large part Samsung's detailed response to Apple's claims that due to copying tactics employed by the Asian tech giant in competing to the lucrative smartphone market, the U.S.-based firm lost some $US.2.5 billion.

Apple wants the same amount in part to settle the U.S. episode of its ongoing global patent wars with Samsung.

The tech giant has accused Samsung that it became the biggest smartphone maker in the world at the expense of other company's creative genius.

Samsung, however, informed the U.S. federal court that Apple was hardly an original creator and innovator that it claims to be since the first product that led to billion of profits for the firm was partly based on Sony PDA models, which IDG News has identified as Sony Clie.

Apparently, the Sony PDA in subject had tickled the interest of the late Steve Jobs due to its "designs that lacked 'excessive ornamentation' such as buttons, fit in the hand, were 'square with a screen' and had 'corners (which) have been rounded out."

Samsung provided what it claimed as Apple's internal documents that proved Mr Jobs sought to interview designers of the Sony product, which allegedly inspired Apple' first iPhone designs, then touted by the tech titan as its way of reinventing the mobile phone.

But in a report by IDG News on Thursday, it noted that the photo of the mock-up designs for the first edition iPhone, which was provided by Samsung as supporting evidences for its arguments against Apple's accusations, looked more like the iPhone 4 and the iPhone 4S.

The CAD-generated designs, purportedly for the first generation iPhone, carried flat front and back and its edge was accentuated by a silver plating, IDG News said.

The first iPhone was unveiled in January 2007 with curved edgings, which clearly departed from the designs that Samsung claimed were first produced by Apple.

Nonetheless, Samsung insisted that it "does not infringe any of Apple's patents and has located dead-on prior art that invalidates them."

The company stressed that technologies, which Apple said were exclusively its intellectual properties, "were developed and in widespread use well before Apple entered the mobile device market in 2007."

The Asian firm informed the court that contrary to Apple's accusations, it has started re-designing its next generation of smartphones as early as the summer of 2006, which were "based on the market trend of ever-increasing screen size."

In accompanying photos submitted by Samsung, the company showed that "Samsung's designers envisioned a basic design: a simple, rounded rectangular body dominated by a display screen with a single physical button on the face."

Samsung stressed that it did not implement a design overhaul on its products because Apple issued a blockbuster product that set the pace for the smartphone market five years ago.

"Samsung independently developed the allegedly copied design features months before Apple had even announced the iPhone. It did not switch its design direction because of the iPhone," Samsung argued.