Police have said they are treating the large blaze in Corby, where stacks of pallets measuring six metres high caught fire, as arson.
Four fire crews were called to the scene of the fire in Heritage Way, Corby, just before 6.40pm on Thursday, May 16.
The stack of pallets measured 150 metres by 100 metres.
A police spokesman today (Friday) said: “Offender(s) gained entry to a business premises and set a large number of pallets alight, causing substantial damage.
“Officers would like to hear from anybody who witnessed the incident, or who saw or heard anything suspicious.”