A member of Parliament is demanding reassurances that nothing remains of an anthrax bomb tested in a south Wales estuary during World War II.
Nia Griffith made the call after it emerged the weapon was dropped off the town's coastline, according to a story on the BBC on Oct. 30.
There have been concerns about water quality and the death of cockles in the Burry estuary.
The Ministry of Defense said there was no contamination following the experiment in 1942.
The trial to test the biological weapon emerged in an article written by historian Gerald Grant, of Llanelli, Wales.
Griffith has now written to the Ministry of Defense asking for further details.
"We know there was a lot of research going on during the war into germ warfare and we know this was an area that may have been used," she said.
"Obviously, all of that is top secret and they will have to look through a fair number of documents to give us the answers we want.
"What we really need to know is clarification — what did happen, what were they handling, and what were the consequences and was everything cleaned up?"
Local councilor Hubert Hitchman said there had been long-standing rumors anthrax weapons had been tested in the estuary between Llanelli and Gower.
"To test it so near populated areas is ridiculous," he added.
A spokesman for the Ministry of Defense said: "The Gower coast was often used for munition testing during WWII.
"However, a bacterial weapon was only tested once, in 1942, when a 30-pound bomb charge with anthrax spore was dropped from a Blenheim aircraft at 5,000 feet.
"There was no residual contamination of the site as it was washed by the incoming tide. No other biological weapons trial was done at Penclawdd and no other species of bacteria were used."