Contractors hired by Environment Agency Wales have removed an unmarked oil drum from the car park of the Little Chef restaurant in St. Clears.
Agency officers were called to the site, last Thursday afternoon where a rusty, blue, 45 gallon oil drum was found abandoned in the corner of the car park.
The unmarked oil drum presented a potential risk to the environment and the public and was secured and removed to a safe location for further investigation.
Doug Cowie, environment officer, Environment Agency Wales said: "We responded quickly to remove the oil drum and minimised the potential risk to the public and the environment.
"Agency officers worked in partnership with other organisations, including Mid and West Wales Fire and Rescue Service.
"We are now seeking information from anyone who could help us with our investigations. Please contact us on our 24-hour hotline 0800 80 70 60. Calls are free and will be treated in the strictest confidence."