Humberside Fire and Rescue service were alerted to the incident at the factory on Athenian Way in Grimsby at 11.50pm. Two appliances were initially sent to the scene from Peaks Parkway fire station, with another pump and hydraulic platform called in for further assistance.
The fire was understood to be next to a large oil tank, prompting firefighters to focus their attention on it in order to stop any possibility of ignition.
Fire crews said the blaze was under control by 2.12am and they left the scene about half an hour later, with the fire deemed to have started accidentally.
Meanwhile, up to 400 jobs are currently at risk at Five Star Fish after 2 Sisters revealed plans in March to enter into consultation with colleagues and customers at the “loss-making site”.
At the time, 2 Sisters said the fish firm had undertaken a full strategic review of its business and concluded that the operation was “not sustainable in its current form for the long-term”. Five Star employs 390 staff at the site.
“We are having ongoing discussions with our customers and with other local manufacturers to ensure we explore the full range of options available to us,” said 2 Sisters.