It was discovered during a number a searches on Thursday night.
Officers and student officers attended a number of incidents, including 3 domestic ones.
Knuckle dusters are banned from being imported, made or sold in the UK.
It is also a crime to carry such a weapon in a public place.
Fire destroys two part-built houses on new development
Two derilict buildings destroyed
Devon man to run round mainland Britain
Steve Jones will be first man over 60 to do so, if he makes it
Decision on Exeter swimming pool due this week
Protests gather pace
South Hams tourism down, but average spending up
Sector is worth £266 million to the district
More East Devon council workers leaving
One in eight quit last year
Dartington pool expected to reopen
Developers stumping up £88,000
