A 63-year-old man was also arrested at Peter Boddy Slaughterhouse in West Yorkshire, the other plant where operations were suspended on Tuesday in an investigation by the Food Standards Agency.
Dyfed-Powys Police has confirmed three people are being held on suspicion of offences under the Fraud Act.
They are being detained at Aberystwyth Police Station, where they will be interviewed jointly by the police and the FSA.
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Updates on Swansea City, Cardiff, Wrexham and Newport County.
There will be some light rain but it's mostly dry with sunny spells developing.
The UK has experienced a 4.4 magnitude earthquake. The epicentre was Cwmllynfell near Pontardawe in the Swansea Valley.