More than 40 burglaries across the Lewes, Wealden and Horsham districts are now being linked by detectives.
The offences began in August in Storrington but have spread to Coolham, Henfield, Steyning, Horsham, Pulborough, Bramber, Billingshurst, Kirdford, West Chiltington and Ashurst as well as Petworth in the Chichester district.
They have also spread to Durgates, Ringmer, Buxted, Lewes, Maresfield, Pell Green, Newick, Isfield, Cross in Hand and Uckfield in East Sussex.
The most recent offences linked to the offenders happened in Rapley Avenue, Palmer Close and Dean Way, Storrington, on November 19.
In each case the thieves broke into the homes through a back door or window, searched the properties and escaped with selected items of jewellery and valuable items, such as the ornamental plate pictured.
The victims have included people that have gone on holiday and elderly residents whose homes have been targeted within days of them moving into care homes.
Sussex Police launched Operation Magpie to tackle burglary across the county.
Officers believe the offenders could be cold-calling at homes to try to work out who is in and whether they are likely to have valuables inside their properties before returning later when the addresses are empty.
CCTV footage of a man breaking into a home in Kings Barn Lane, Steyning, on August 14, one of the 45 burglaries being linked to the offenders, has now been released in the hope that residents can identify the man involved.
To watch the footage visit www.youtube.com/watch?v=_lu7js0FgK0.
Katy Wood, from the Operation Magpie team, said: “”We urgently need the public’s help to identify who is responsible.
“Don’t let cold callers into your home and please report anyone acting suspiciously in your home or nearby to us immediately.
“Please consider fitting an alarm if you don’t have one, fit timers to your lights so they do on when you are not there and make sure you leave your home secure.
“If you see someone behaving oddly at a neighbour’s home call us - we would rather come out for a false alarm than miss the chance to arrest a burglar.”
If you see or hear a burglary taking place call 999 immediately.
Residents are also being encouraged to register their items on the world’s largest property database so that if they are stolen, they can be reunited with the owners - and so the offenders can be prosecuted.
You can register your property in just a few minutes by visiting www.immobilise.com. To watch a video about Immobilise and how it works, visit www.youtube.com/watch?v=0XZ66WEER_c.
If you have any information about burglaries email firstname.lastname@example.org, call 101 or contact the independent charity Crimestoppers anonymously on 0800 555111.