A group of burglars are now believed to be responsible for more than 200 break-ins – including more than 20 in and around Crawley and Horley.
Sussex Police said a group of up to a dozen burglars had been involved in 59 offences in Sussex, 24 in Surrey, 113 in Kent and nine in London since September.
Between Monday December 8 and Sunday December 14, 18 burglaries were committed in Sussex that are being linked to the group along with four in Surrey and 22 in Kent.
On each occasion the offenders have driven to their victims’ homes in a silver or dark car, usually an Audi or BMW, before breaking in at the back of the properties and stealing cash, jewellery and electrical items.
The thieves are believed to be using cars fitted with numberplates that have been cloned from another unrelated car of the same type and colour. Officers would like to speak to anyone who sees people changing numberplates or who finds any abandoned plates.
Detectives are also urging residents to help them catch those involved by dialling 999 immediately if they see people acting suspiciously near their homes - in particular if they notice potential offenders with silver Audis or BMS.
Detective Chief Inspector Richard Clay of Surrey Police, who is leading the investigation, said: “There are detectives from across the south east working to catch those involved but we need the public’s help.
“The key to identifying the people responsible may come from residents living near one of the victims. They may have seen the thieves escaping in their silver car or could have seen people acting suspiciously over the weekend.
“I would also urge people to continue to be vigilant in their areas and to tell us if they see anyone who is acting unusually near their homes. If something sticks out as suspicious to you, please tell us so we can investigate - it could be the break that we need to catch those involved.”
A reward worth up to £10,500 has been put up for information that leads to the arrest and conviction of any of those involved in the burglaries.
Sussex Police, Kent Police and Surrey Police have each contributed £2,500 to the reward along with £3,000 from the independent charity Crimestoppers.
Anyone with information should email email@example.com or call 101 quoting Operation Smart.
Alternatively, contact Crimestoppers anonymously on 0800 555111.