HMRC have taken more action in their ongoing campaign against carousel fraud.
Early morning raids in Scotland led to the arrest of six people, and four properties (three domestic and one commercial) were searched.
Officers were investigating a suspected £20 million VAT fraud ring, as part of the Revenue's Operation Vaulter.
The crackdown began two years ago, and resulted in the apprehension last September of 17 suspected fraudsters.
All those arrested so far are believed to be part of an organised gang dedicated to money-laundering and missing trader intra community fraud.
They are suspected of having bought large quantities of mobile phones and other low-volume, high-value goods from EU countries and then sold them on in the UK without paying the VAT due.
Chris Harrison of HMRC's criminal investigations unit said: 'Tackling missing trader fraud is HMRC's top priority.
'The sophistication of the organised crime gangs behind these [crimes] means that our investigations are increasingly complex, but we are committed to… recovering the money stolen from the British taxpayer.'