An electrical fault is believed to be the source of the “heat build-up” at the Bernard Matthews factory near Halesworth which saw nine fire crews scrambled.

The fire service said they were called to attend the warming of a cold store building at the industrial estate.

They said external refrigeration units to the cold store were showing signs of heat build up, but could not confirm whether or not there was a blaze, despite the possibility of “several small fires” causing the warming.

An electrical fault is believed to have caused the units to overheat due to a faulty cooler unit leading to a lack of ventilation was to blame for the build up.

The fire teams on scene used breathing apparatus as a precaution while attempting to ventilate and cool down the units, which was successfully done by 10pm when crews were stood down.

Nine crews were initially sent to the scene with four stood down in the early stages of the incident.