The Electoral Commission says it will conduct a review of the PCC elections, warning that record low participation levels of well below 20% were "a concern for everyone who cares about democracy".
A 'detailed inquiry' will held into the Police and Crime Commissioner polls. In Gwent, only 14.3% voted - many places saw no ballots at all.
Independents take North Wales and Gwent, while the Conservative candidate wins in Dyfed Powys. Labour wins in the South Wales region.
Counting will get underway later this morning, in elections for new Police and Crime Commissioners for each of Wales' forces.