Git GUI on OS X with remote over SSH fails with "remote hung up unexpectedly"

When using the desktop icon generated by git-gui to start the visual user interface I am not able to fetch or push changes to my remote repository. I am using SSH to access my repository and have configured public / private key authentication so I don't have to provide a password when accessing the git repository every time. When using the command line to push / pull / fetch everything works great, however when using the git-gui when started via the desktop icon I get the following error: "remote hung up unexpectedly".

When I start git-gui via the command line it also works properly. So instead of using the generated desktop icon I put a quick command / script together to navigate using cd to the repository directory and then to call the git gui command. The downside of this is that every time I start this i also get a terminal window. 

I am guessing this is because the git-gui can't find the ssh command. I have tried to update the path in .MacOSX/environment.plist manually to include /usr/bin but this didn't help either. Also having had a look online didn't provide any obvious suggestions.

Kind regards Alex