Fools' Copper (not to be confused with Ghost Beer)

1977. Nick & Rosemary Storey's help is sought by the EEC Commission to track down those responsible for fraudulently claiming money from the EEC's Regional Development Fund to convert a former copper mine in North Wales into a tourist attraction.
As they pursue their enquiries, they come across "ghost beer", illicitly-produced beer which is being sold in North Wales and the Borders. Unmasking a crooked bank manager appears to lead to a dead end, as the "fixer" for the EEC fraud was run over - probably deliberately - eight months earlier. Trying to follow a cold trail in the valleys of Snowdonia, Nick and Rosemary are shot at. However, traces of evidence and links eventually lead them to an extraordinary and bloody conclusion to both cases.
"Fools Copper" is the eleventh book published in a series of detective stories mostly set in Customs & Excise by Richard Hernaman Allen, a former Commissioner.