Nokia's chief technology officer Rich Green has taken a leave of absence from the mobile phone giant.An official Nokia statement said he had left to resolve a "personal matter" and gave no date for his return.
However, a Finnish newspaper quoted sources inside Nokia saying he had left because of differences over strategy and would not return.
Mr Green was known to champion the MeeGo mobile operating system which Nokia recently sidelined.
That decision was brought about by Nokia boss Stephen Elop's decision to adopt Microsoft's Windows Phone software for its smartphones.
Tech change Finnish newspaper Helsingin Sanomat cited unnamed Nokia sources who claimed that Mr Green's departure was linked to the MeeGo decision. In particular, it said, Mr Green was unhappy with Nokia's decision to abandon plans to produce phones built around the system.
In its statement, Nokia said Mr Green's absence would have "no impact on our product strategy or our expected product launch timelines".
Rich Green joined Nokia in early 2010 following a 19 year stint at Sun Microsystems where he latterly oversaw the move of Java code onto mobile phones.
When he was appointed, he was Nokia's fourth chief technology officer in five years. The company said that Henry Tirri, currently head of Nokia's research labs, will take over the post of technology boss.
The news of Mr Green's departure caps a rough month for Nokia in which it announced that sales of its phones during the second quarter of the year would be substantially below previous forecasts.
Ian Fogg, an independent industry analyst, declined to comment specifically on Rich Green's departure but said the transformation Nokia was currently going through was fast and far reaching.
Senior management at Nokia have had to make some very hard decisions about its older projects and products, he said, adding that the strategy switch to Windows had to take the entire company along with it.
This was essential to ensure Nokia could get on with the job of producing Windows Phone handsets, explained Mr Fogg. However, he expressed concern that the company was moving fast enough.
"Nokia has to bring Windows Phone devices to market quickly," said Mr Fogg. "It has to execute faster. They need those devices to be shipping."