Two directors have been arrested on suspicion of money laundering.
They were taken into custody from their home in Berkhamsted by HM Revenue and Customs and Herts and Beds police on Thursday.
The home and a Dunstable business have been searched, and the man, 46, and woman, 50, were bailed until December 13. Investigations are ongoing.
Adrian Farley, assistant director for HM Revenue and Customs, said: “HMRC take money laundering and tax fraud seriously and will not hesitate to investigate those suspected of stealing public funds.
“Anyone with information about individuals who may be involved in tax fraud can contact the Tax Evasion Hotline on 0800 788 887.”