Customs officers have seized 86 illegal gaming machines from four amusement arcades, including one arcade in Brighton.
The seizures were made last week and led to the arrest of a 45-year-old man in Bognor Regis on suspicion of gaming duty fraud.
Revenue and Customs said that the unlicensed machines contained almost £20,000 cash.
Revenue and Customs spokesman Bob Gaiger said: “We are investigating the non-payment of approximately £100,000 in amusement machine licence duty since July 2011.
“Gaming machine operators are legally required to pay the excise duty due on each machine, and if they don’t, then our officers step in.
“We only seize machines as the last resort when all other efforts to collect the duty have been exhausted.”
Officers raided arcades at undisclosed addresses in Brighton, Bognor, Crawley and Tunbridge Wells and two homes in Bognor.
The man who was arrested has been released on bail until Monday 20 August while investigations continue.