A man who tried to import a weapon and have it sent to his home in St Neots was caught after the package was intercepted on the way.
Wesley Stevens, of Countess Close, Eaton Socon, tried to import an extendable baton earlier this year but the package was halted on its journey by Border Force officials.
Information was then passed to the police and officers from the southern Community Action Team (CAT) began their investigation, also later conducting a warrant at Stevens's home.
Stevens, 20, pleaded guilty to importing prohibited weapons with intent to evade a prohibition at Cambridge Magistrates' Court on Friday (20 December).
He was handed a £120 fine by magistrates as punishment. However by committing the offence he breached a suspended sentence and was ordered to carry out that sentence by spending 28 days behind bars.
Constable Ben Shayle, of the Southern Community Action Team, said: "This case not only highlights the consequences of breaching a suspended sentence, but also what could happen if people are caught in possession of an offensive weapon or try to import them.
"No matter what your reason is for bringing these weapons into the country, they have no place on our streets. It is illegal to import them as well as possess them in a public place.
"We are actively pursuing those who buy, import or possess offensive weapons - conducting warrants and interviews to put cases before the courts.
"Tackling serious street-based violence is a priority for the force and we will continue to work tirelessly to take weapons off of streets."
For more information about possessing a knife or an offensive weapon in public, and the laws surrounding it, visit the force website: https://www.cambs.police.uk/information-and-services/Firearms-and-shotguns/Knife-gun-crime
Further guidance on offensive weapons can be found here.
Know someone who carries a weapon? Please help us tackle serious street-based violence and report it to us by calling 101 or visiting www.cambs.police.uk/report. Alternatively, contact Crimestoppers anonymously on 0800555111 or via www.crimestoppers-uk.org.