Police are appealing for sightings of a teenage girl hours before she was found dead near a pond.
The body of 18-year-old Lily Sullivan was found at Pembroke Mill Pond shortly after 4am on Friday morning.
Dyfed-Powys Police said a 31-year-old man has been arrested on suspicion of murder and remains in custody.
Lily Sullivan's body was found at Pembroke Mill Pond in Wales.
Family Handout
Detectives have released a photograph of Miss Sullivan taken hours before she died in the hope witnesses recognise her clothing.
They want to speak to anyone who saw the teenager in the Main Street area from 7.30pm on Thursday and in the Mill Pond area from around 2am on Friday.
Miss Sullivan was wearing a white cropped top, blue jeans with ripped knees, white belt and black patent boots.
She had a spider tattoo visible on her chest, and had black hair, which was bleached at the front.
A force spokesman said: “Her family is being supported by specialist officers.
“A 31-year-old man arrested on suspicion of murder remains in police custody at this time.
“Anyone who may have information that could assist the investigation is asked to get in touch.”