The blaze which shut Bicester Village for five hours started from an ‘accidental’ electrical fault, according to the fire service.
A blaze broke out at Bicester Village last Wednesday morning and it needed 35 firefighters to tackle the flames.
Seven crews used an aerial platform ladder to put out the fire which spread quickly and destroyed the roof of the building.
The shopping village was shut for five hours and an investigation was launched.
But the fire service has now completed its investigation and await further results from forensics.
A spokesman for Oxfordshire Fire and Rescue said the fire was ‘accidental in nature and caused by an electrical fault’.
He said: “Forensic investigators continue to work to pinpoint the precise nature and cause of that fault.”
Crews from Bicester, Wheatley, Eynsham, Banbury, Kidlington, Deddington, Oxford & Buckingham all battled the blaze but no one was injured.
A dozen shops remained closed the next day but all reopened for the Easter weekend.