Some time ago I had a little accident with my bike. With the accident the front wheel got unaligned from the handlebar.

I simply put it in the right position holding the wheel with my legs and turning the handle bar. Easy solution.

Since than the wheel has a strange behaviour. If I let go of the handle bar when riding the wheel (and handle bar) turns right "automatically". Do you have any idea of what is happening?

Note: Initially I thought it could be a warped wheel but it doesn't seem to be the case.