Police have issued pictures of a number of dogs thought to have been stolen.
A raid on a site in Surrey on 16 March, led by Sussex Police, recovered 10 spaniels and lurchers.
One of the dogs, a two-year-old cocker spaniel named Willow, was found to have been stolen during a burglary in Suffolk and has now been returned to his owners.
A 30-year-old woman, arrested on suspicion of handling stolen goods, has been released under investigation.
Det Chief Inspector John Wallace, of Crawley CID, said: "We are desperately seeking the lawful owners of the remaining dogs which were seized in the recent warrant.
"We appreciate this has been an agonising time for those members of the public with missing pets who have been waiting for further information".
In January Sussex Police launched 'Operation Collar', dedicated to dog thefts and led by the Rural Crime Team.