A 14-year-old boy has been arrested and bailed following an allegation of sexual assault on a 12-year-old girl.
South Wales Police said officers were investigating an alleged incident near Dinas Powys skate park, Vale of Glamorgan, on Wednesday, 4 August.
The arrested teenager is from Sully, Vale of Glamorgan.
Police have appealed for witnesses. A spokesperson said: "Incidents of this nature are extremely rare and Dinas Powys is a very low crime area."
Anyone with information is asked to contact Det Con Nick Miller at Barry CID on 101; or call the independent charity Crimestoppers on 0800 555 111.