Warehouse owners have been told to tighten their security after an illegal rave took place on an industrial estate last month.
Police and the council have been in touch with the owners of industrial units to encourage them to review their security including lighting and CCTV following a rave that attracted more than 3,000 young people to an empty unit in Bath House Road, off Beddington Lane, overnight on Saturday, April 19.
Police believe the organisers targeted the warehouse, which was due to be leased to a tenant days later, for weeks while they arranged the event.
Police first became aware of the event as large numbers of people flocked to the area on Saturday evening.
It is understood people registered their interest online before details of the event were sent out at the last minute.
The party caused thousands of pounds worth of damage and police are investigating.
Officers are working with British Transport Police and Transport for London as they believe party-goers will have used the rail network to get to the event.
Business owners have been sent letters encouraging them to secure their buildings and notify the authorities of any nearby warehouses that could be vulnerable.
Large events such as this need authorisation from the council, which will consult police as part of the process.
If anyone believes such an event is being planned near them, they can call police on 101.