Around 60 firefighters attended a blaze at the Wicken Fen vegetarian food factory in Duns at around 11.15pm on Sunday June 19.
Eight firefighters wearing breathing equipment, using hoses and a turntable ladder as a water tower were required to extinguish the fire.
The victim has been named locally as company employee Brian Newton, and a spokeswoman for Lothian and Borders Fire and Rescue Service said:
"Tragically there was one male fatality at the scene. The fire was finally brought under control at 5am today. An investigation into the cause of the fire is under way."
A police spokesman said there was nothing to suggest suspicious circumstances, although enquiries were at an early stage: 'Tragically, this fire has resulted in a fatality and we are now investigating along with Lothian and Borders Fire and Rescue to establish the events that led to a man's death.
“Anyone with information that can assist with the investigation is asked to contact police immediately.”