Police in Northampton discovered a surprise haul of items after a routine stop search.
The Proactive Team stopped the man in a Northampton street on Saturday and found his underwear contained "numerous phones" as well as cash.
Officers later searched his room and discovered almost £10,000 in cash, some Class B drugs and a hunting knife with a 20cm serrated blade.
The suspect was later arrested.
It was another busy day for the plainclothes Proactive Team, who specialise in stopping drug dealers and violent criminals.
Officers also stopped two men who were seen exchanging some items.
One was arrested for supplying drugs and proceeds of crime.
In custody, he too produced illicit items from his underpants, this time some deal bags and cannabis.