Police seized around £10,000 in cash from a property in Keighley yesterday.
Officers raided a property in Black Hill Lane, Braithwaite, as part of a major crime crackdown across Bradford district.
The officers, working under Operation Viper, found a large quantity of cash in the bedroom and bathroom.
A 25-year-old man was arrested at the scene on suspicion of money laundering and was later been released on police bail.
Operation Viper operated through the week as part of a concerted effort to target prolific and persistant offenders in the district.
During five days of action 31 people were arrested and 97 premises were visited.
Police seized six vehicles and a number of weapons including tasers, crossbows, swords and knuckledusters. Officers have also found and dismantled three cannabis farms.
Chief Superintendent Dickie Whitehead, who led the operation, said: "We have taken the fight right to the doors of some of the most prolific offenders operating in the district and ensured that a significant quantity of drugs and dangerous weapons have been taken off our streets.
“It is just one of a number of proactive tactics we are employing under Operation Viper to ensure that there is no hiding place for criminals in the county."