In short - we all agreed we have equal ownership of the source code.
In writing? And, what is meant by ownership of the source code? Ownership of property is the right to exclude others from access to the property. Was the source code to remain secret? --> trade secret. Was the ability to make copies of the software or to amend/improve the software to be limited? Copyright. Was the partnership to own all storage media on which the software is physically stored? Not sure what that is.
What other rights?
Point one is can any of the owners sell the software in the current form - setting the distribution of the source aside.
What do you mean by "sell"? Assign all copyrights, trade secrets, etc. in the source code? License end users for use of the software?
I don't have answers because I still don't understand who owns what.
The person who was employed by the Company as the programmer is also a share holder in the company but not a Director.
Neither of those roles matter here. An officer (hired by the board of directors) would have a fiduciary duty to the corporation. i.e., a duty of faithfulness and loyalty.
The partnership (ownership) of the source is held by the three of us and a note was put in the Articles of memorandum and association of the limited company stating that it (the company) could sell and develop the software but not own it. No royalty agreement was agreed.
Well, that sort of stuff is better done by contract with the partnership rather that put in the Articles.
Is there any reason that all the owners could not have the equal right to sell the current product.
Could be several reasons.
First thing to do is figure out who owns the source code. Let's stick to copyright for now because that's the one I'm most familiar with. And, like I said, you'd do well to ask these questions in the Copyright forum and Trade Secret forums. You also need help with business entities, but that's outside the scope of these forums.
Originally, the copyright is owned by the author -- in this case, the developer. There are only two ways to get ownership from the author. One is automatic: if the work is created incident to his employment as a regular employee (and not a contractor), the employer owns the copyright. The other is assignment by contract.
The fact that the corporation was specifically prohibited from ownership of the developer's work hints that the developer's work in writing the software was not as a regular employee of the corporation.
Then, there's the question as to whether there was a specific contract between the developer and the partnership.
Was the project reasonably completable in less than one year? If so, it might be possible to enforce an oral contract. Otherwise, a written contract would be required.
How to sort out whatever sort of contract you might have is well beyond what I do.
Regards.