The project, which the Finnish company designed with Intel, has lost Sotiris Makygiannis, who held the title of MeeGo development lead.
Tweeting his plans to leave the company, Mr Makygiannis wrote: “After 12 years at #Nokia is time to say goodbye. Last day but I'm going knowing that we created a legendary phone #N9 and Finnish mobile phone maker Nokia appears to have almost completely buried one of its most popular projects, the MeeGo OS, which landed on shelves inside the highly-appealing Nokia N9 smartphone."
According to rumours, he has been followed to the exit by a few more members of the team who also announced plans to leave.
However many of them will continue to work with the platform, moving over to CloudBerryTec, where they will be able to build applications for the OS.
This isn't the first time the MeeGo project has faced problems. Last year a raft of staff walked out after the company announced plans to adopt Microsoft’s Windows Phone.
And it seems MeeGo has also been abandoned by its partner Intel, which was forced out of the picture after Nokia decided to partner with Microsoft.
A spokesperson for the company refused to comment on the latest walk out, claiming it was "a Nokia story" - suggesting that it wants nothing more to do with the company.
Last year it seemed to be considering a range of options for the flagging system including turning it into an operating system for a car.