Three fire engines and around 15 firefighters remain at the scene of the fire at a self-storage warehouse on Purley Way in Croydon.
At the height of the fire, the whole of the four storey building was alight.
Assistant Commissioner Graham Ellis, who was at the scene, said:
"This was a significant fire at a self-storage warehouse with a large amount of fire loading inside the property which made it a very challenging incident.
“As you can imagine, self-storage units are generally full of items like furniture which, when packed tightly, provide a lot of materials to burn and so these sorts of incidents tend to create large fires that burn hard for a long time, creating a lot of smoke. That said, firefighters have worked hard to ensure that while the fire is burning, it is contained and won’t spread to nearby buildings. While firefighters remain at the scene, we would continue to urge locals in the area to keep windows and doors shut.
“Self-storage units are technically very difficult fires to manage as it’s difficult to know what is being stored which is another reason why we have fire appliances in the area. This is causing a lot of disruption to local roads and Purley Way remains closed. We are working very closely with the police, TFL and local businesses to ease the congestion but if you can avoid the area, please do.
"Thankfully there were no reports of anyone inside the property at the time of the fire and there were no injuries."
Purley Way has reopened along with other main roads in the area.
The Brigade was called at 1947 on December 31 and the fire was under control at 1756 on January 1. At the height of the incident, 20 fire engines and around 125 firefighters were at the scene.
The cause of the fire is under investigation.