Four arrests were made by police and £20,000 discovered under a bath by a police dog.
Police stopped a van on Chaddock Street yesterday (1 July) in what they described as a proactive vehicle stop.
Several thousand pounds in cash was recovered and three men were arrested at the scene.
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A search of nearby addresses found several kilograms of vacuum packed cannabis hidden in a loft, two established grows and £20,000 hidden under a bath in one of the properties. A fourth man was arrested.
The men, aged 22, 28, 28 and 36, are currently in custody being questioned on suspicion of cannabis cultivation and money laundering.
A spokesperson for police said: “Preston Taskforce stopped a suspicious looking vehicle leading to two arrested for drug and money laundering offences.
“This led to a house search where PD Buddy was asked to assist. He made light work of locating approximately £20000 cash well hidden under the bath!”
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