If you want him to stop following you. Your best bet is to ignore him. The more you interact with him the more he's going to assume you're playing with him. If you're worried that people might make wrong assumptions about you being the owner, start wearing headphones during your walk, body language in general can be quite helpful.
If you're trying to leash him, a pole snare for dog catching would be a good investment. Might need some practice and you might need someone else to help too.
There are also sedatives that are relatively safe that you can use to lace his food with although you'd have to be careful that the wrong animal doesn't eat it and I doubt you'd be able to get a vet to prescribe you any of those drugs without first having examined the animal.
Honestly, I'm more surprised that animal control hasn't been able to catch him because really this isn't your responsibility.