  Different proposals for regular rotating black hole spacetimes have appeared
recently in the literature. However, a rigorous analysis and proof of the
regularity of this kind of spacetimes is still lacking. In this note we analyze
rotating Kerr-like black hole spacetimes and find the necessary and sufficient
conditions for the regularity of all their second order scalar invariants
polynomial in the Riemann tensor. We also show that the regularity is linked to
a violation of the weak energy conditions around the core of the rotating black
hole.
