My brother claims to be in this position.
I'm divorced with two kids and have a lovely amicable relationship with my XH. I can't understand why anybody would willingly cut off support from the other parent without good reason. Bringing up children on your own is extremely hard!
So I would like to hear from people who honestly feel they have done nothing wrong and yet the ex partner refuses to let them have access to their children, people who have cut off contact with their children's parent for what they think are good reasons ( not abuse, though, as obviously that is a given), and people who want their children's parent to have contact but have heard that the parent is going around saying that they have refused access when they haven't.