A trial in which residents have put details about local crime into police boxes could be expanded into other parts of London.
Residents in Harrow have been encouraged to drop information about crime and community issues into the boxes since June last year.
The scheme aims to make it easier for people to give information anonymously.
Following talks with other police divisions, Harrow police say it could now be rolled out across London.
There are about 12 boxes in the borough located in public buildings such as schools, supermarkets and newsagents.
Each box has forms which residents can fill in to give detailed information about their concerns.
Police Community Support Officer John Duggan came up with the idea.
"I felt that we needed an extra link between the community and the police," he said. "It's a great way of them putting anonymous information in that we can build on."