Police have seized £260,000 in cash, including £60,000 in a car in Gillingham.
Police discovered cash when the vehicle was stopped in the Wigmore area.
The stop in Maidstone Road in September 2018 led investigators to start the inquiry and traced money back to a house in Nottinghamshire.
A further £200,000 was discovered inside the property in what is now being treated as a suspected money laundering network by the Kent and Essex Serious Crime Directorate.
Jonathan Oscroft, 32, of Broad Valley Drive, Nottingham, Jay Taylor, 32, of Carnarvon Grove, Nottingham, and Omerfaraz Rahman, 39, of Woodside, Gillingham, have all since been charged with money laundering offences.
They were granted bail after appearing before magistrates.
All three will appear at Maidstone Crown Court on July 10.