Ignition barrel issues EE90 / AE92

[Leon]

Right, picked up a hack car EE90.

On the way home, I turned the key off, and it went back past "lock" and jammed. To cut a long story short, had to have the ignition barrel pulled out to make anything work again.

Does this sound like a worn key, or does it sound like I have a knackered ignition barrel (or some other problem).