ORIGINAL: annie_himself
Since it won't release your engine could be flooded or even hydrolocked. Lets hope not, but try to get the gas out then start it.
Good Point
If this is the problem, take out the glow plug and give the engine a few tugs. Fuel will spray out, then reinstall the plug and try again.
Also, I would carefully take off the starter. As you are taking it off, try not to disturb any of the internal parts on the starter as re-coiling it is a pain. Usually when I do this the oneway bearing is remaining on the starter shaft. From here you can try to turn the bearing in order to see if it is functioning properly.
Ryan