The playgroup was closed temporarily
A person arrested on suspicion of sexual assault at a Aberystwyth playgroup will not be charged, say police.
Dyfed-Powys Police said the Crown Prosecution Service had decided there was insufficient evidence to charge and no further action would be taken.
The person was arrested in connection with the allegation at St Padarn's Playgroup in February.
The playgroup was closed for a time following the arrest.
A police spokeswoman said: "Dyfed-Powys Police has concluded its investigation and a file has been presented to the Crown Prosecution Service (CPS).
"The CPS has examined the evidence and assisted the police from the early investigative stages of the case through to its conclusion.
"After a thorough examination of the evidence, the CPS has concluded that there is insufficient evidence to charge, and thus no further action will be taken against the person arrested at this time."
Dyfed-Powys Police said they, and the CPS, took all reports of sexual assault seriously and investigated all allegations with specially-trained officers and prosecutors.
The playgroup is independent of St Padarn's Roman Catholic school.