A year ago, I did work for my friend Jonathan who found us a client. The client had a person called Andrew working for him. A year later, Andrew is now working for a totally different company approached me for work as he remembers I did a good job at the previous company he worked for. Jonathan now wants me to give him a certain percentage I get from this new company every time they give me work to do. Is this really the case? I sub contracted for Jonathan I never had a permanent job with him.
What is stipulated in the contract that you signed with Jonathan. That should give us a good idea of what the terms of contract were, and they are binding even after you leave the company, because this is what you agreed to.