Five appliances and 21 firefighters attended the fire, which started in the South Wales-based company's paper warehouse at 2.23am.

According to a spokeswoman from South Wales Fire and Rescue Service, the fire was extinguished by 4:25am, and the last firefighters left the scene at 8:30am.

Pensord's managing director Darren Coxon said the fire started in the company's paper warehouse, which is in a separate building to the main production facility.

He said: "Initial feedback from the police and fire personnel attending indicates that unauthorised people broke into the property early this morning and lit two fires at the office end of the store, damaging some of the paper pallets and an office.

"The fire brigade attended quickly and extinguished the fire quickly. No-one was hurt, and production is continuing as normal."

He added that the fire damage is limited to an office, paperwork archive and some pallets of plain paper.

The spokeswoman for South Wales Fire and Rescue Service confirmed that it was believed that the fire was started deliberately, although no further information was available at this time.