HM Revenue & Customs is responsible for investigating any criminality (as well as civil fraud) in relation to tax. It does not have its own prosecuting powers, but instead will investigate wrongdoing and submit its findings to the CPS for a decision on whether it will prosecute.
To assist with its investigations, HMRC has statutory powers to:
• apply for orders requiring information to be produced - production orders
• apply for search warrants
• make arrests
• search suspects and premises following arrest
Further information about HMRC's powers can be found here.