Dyfed Powys Police and the FSA will today begin interviewing the three men arrested on suspicion of offences under the fraud act.
The arrests follow a joint operation with the FSA at Farmbox Meats in Aberystwyth and the Peter Boddy Slaughterhouse in Todmorden, West Yorkshire.
Two men aged 64 and 42 were detained at Aberystwyth police station over night and a 63 year old man arrested in Yorkshire has today been transported to Aberystwyth.
Interviews with the three men are likely to continue through the day.
Meanwhile Dyfed Powys Police officers will maintain a presence at the site in Aberystwyth.
More top news
As Welsh-born former Australian PM Julia Gillard speaks at the Sennedd on women's rights, we take a look at some important female figures.
Barry-born Julia Gillard is delivering a lecture at the Sennedd today, where she will discuss barriers women face in the public sphere.
Report into emergency units at Cardiff and Vale Health Board finds a culture of bullying, harassment and inappropriate behaviour