A New Zealand blog has claimed Apple's new iOS7 is set to be released along with the new iPhones on September 10.

According to a leaked email surfacing online at owened.co.nz, a developer named Owen Williams has disclosed messages between software tech company Nuance and app developers.

In an address to NDEV Developers, the company behind Siri says: "As you are probably aware, iOS 7 GA will be released on September 10th.

"The NDEV Program has pre-qualified that SpeechKit 1.4.5 works properly on iOS 7, but we encourage you to conduct your own testing to ensure that when the upgrade happens, your Nuance speech services continue to work seamlessly."

In response to the email, Williams believes that considering Nuance's "intimate involvement with Apple in the past this is as real as it gets outside of Apple itself inviting the media to the event."

Yet Williams acknowledges there’s a chance that Nuance has no idea and is "just hedging their bets that the leaks are right but given their proximity to Apple I wouldn’t be surprised if they did know the date."

Launched at Apple’s Worldwide Developers Conference, 9to5 Mac released an early preview of iOS7 in June.

“The whole OS has that ‘skinny jeans’ Helvetica Nueue Ultra Light or similar that you’ve seen in those posters,” wrote Seth Weintraub at the time.

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