Seventeen people have been charged in connection with a suspected "carousel" VAT fraud involving hundreds of millions of pounds.
The 17 were held following raids by customs officers in London, Manchester and Glasgow early on Tuesday.
They have been charged in Scotland and Revenue & Customs said no details of the exact charges would be released.
A carousel fraud involves goods being repeatedly exported and imported and VAT pocketed.
Revenue & Customs (HMRC) said the operation was the biggest in its history.
They have raided 100 premises - most of which were in Glasgow, Manchester or London.
The operation has so far involved more than 400 customs investigators and 100 police officers.
An HMRC spokesman said: "We can confirm that 17 people have been charged and the case passed to the Scottish procurator fiscal for consideration.
"We cannot say anything else at present due to Scottish law."
The latest official estimates are that carousel fraud cost the UK government up to £1.9bn last year.