An investigation into major smuggling of hand-rolling tobacco and money-laundering has led to a fifth arrest.
Investigators from HM Revenue and Customs (HMRC) searched an address in Rochester, Medway, and arrested a 41-year-old man on Friday.
HMRC criminal investigation assistant director John Kay said it followed four other arrests this month and searches of an industrial unit in Surrey.
Computers, documents and suspected drugs were seized in Rochester.
Mr Kay said investigators had already seized more than three tonnes of hand-rolling tobacco and £400,000 in cash during their investigation.
He added: "One of our key priorities is to identify the abuse of our tax systems by criminal gangs who smuggle illicit tobacco products into the UK for their own profit."
All five people arrested are still being investigated by HMRC.