The Independent Police Complaints Commission (IPCC) is investigating whether South Wales Police acted quickly enough in its investigation into sex allegations against rock singer Ian Watkins.
The Lost Prophets vocalist has been charged with conspiring to rape a child under the age of 13, as well as five other sex abuse charges. He is yet to enter a plea to the charges, but his legal team have indicated that he will be pleading not guilty.
IPCC commissioner for Wales, Tom Davies, said South Wales Police had been provided with information by four different forces prior to Watkins' arrest, and the watchdog would investigate whether or not they "failed to take appropriate and timely action" in relation to the intelligence received.
The matter was referred to the IPCC by the South Wales force themselves.
Mr Davies said: "Following a thorough assessment I have decided that we will carry out an independent investigation.
"Our investigation will determine whether or not South Wales Police failed to take appropriate and timely action in relation to information they were in receipt of in advance of Mr Watkins subsequent arrest.
"We are aware of four forces having provided South Wales Police with information but, as criminal proceedings are active, it would be inappropriate to publish further information at this time."
Watkins and his co-defendants — who cannot be named for legal reasons — are due to appear in Cardiff Crown Court on March 11 for a plea and case management hearing.
Follow EvansTheCrime on Twitter