A 22-year-old man has suffered life changing injuries while working at the Kepak plant in Merthyr Tydfil.
The company confirmed that an incident including a "valued" member of the workforce had taken place and a full investigation was underway.
A spokesman from South Wales Police said the force were called to the St Merryn Foods premises, in Merthyr Tydfil at 1am on Wednesday, February 17.
He said: "Shortly after 1am on Wednesday, February 17, police were called to an incident at the St Merryn Foods premises in Merthyr Tydfil.
"A 22 year old man suffered life changing injuries and was taken to the University Hospital of Wales.
"The Health and Safety Executive is investigating the matter."
The St Merryn Foods plant in Merthyr Tydfil is owned by Kepak and is a meat processing plant.
A spokeswoman for the company said: "Kepak regrets to confirm that a workplace accident, which occurred yesterday at its factory in Merthyr Tydfil, has caused injury to a valued colleague.
"We are currently assisting in every way possible as our colleague receives medical attention.
"A full investigation into the incident is currently underway."
WalesOnline understands the incident happened at the end of a night shift at the site as part of the clean down process. It is believed the man was cleaning a piece of machinery which trapped his arm, however this is yet to be confirmed.
It is understood that police were at the premises all day on Wednesday and that the site remains closed.
A HSE spokesperson said: “HSE is aware and investigating.”
