DYFED-Powys Police are investigating a report that a red Ford ST, registration number CV66 TLJ, was stolen from the public car park at Llanelli Steelworks on Thursday, March 29.
The vehicle was parked there from 7am. It is believed it was stolen at around midday.
The occupants of a grey Kia may have been involved in the theft.
Anyone with information that can help officers with their investigation is asked to report it by calling 101. If you are Deaf, hard of hearing or speech impaired text the non-emergency number on 07811 311 908.