PC Lightfoot urged communities to “keep an eye on” postboxes they thought might be vulnerable and report any concerns to the police.
He said they were working with Royal Mail, using new technology to try and prevent further crimes.
“We’re looking at things like forensic marking, we’re looking at other methods as well.
“We’re trialling 3D scanning software where we’ll build a 3D model of the postbox and then we’ll have a record of what it looks like.
“So if we find one that is stolen, then we can compare it to records of ones we’ve already scanned and prove that that’s from there.”
The spokesperson for Royal Mail said, while postbox thefts were “relatively rare”, if their staff noticed a series of them being stolen, they worked with local police to tackle the issue.
“We appreciate how important access to a postbox can be for a community, and we always aim to balance service provision with practical constraints,” they added.
“Across the UK, we work with Crimestoppers to encourage people to come forward to any details of postbox thefts.”