An investigation into the cause of a major fire at Yusen Logistics warehouse at Sywell Aerodrome Business Park has been completed.
Northamptonshire Fire and Rescue Service (NFRS) was called to the fire shortly before 12.50pm on May 7, with around 15 NFRS vehicles on site at the height of the blaze.
NFRS received more than 100 calls from members of the public about the fire, which caused a significant smoke plume and ash deposits being carried by the wind.
Thick black smoke could be seen, reports suggested, as far as Milton Keynes with chunks of ash scattering a wide area.
A spokeswoman for NFRS said: "The severity of the fire has meant that a definitive cause was unable to be established.
"Although the agreed most probable cause is accidental, due to an electrical failure/malfunction in the distribution board/consumer unit located in the south-west corner of the unit."
In May a spokesman for Yusen Logistics told the Northampton Chronicle & Echo all of the employees at the Sywell site were unharmed and were evacuated to a different site in Northampton.