DMD, you asked me to demonstrate where in law the burden of proof lays with the defendant and not the claimant or words to that effect. Whilst there are differences between civil and criminal law where the latter only requires beyond reasonable doubt, proof generally is required if a prosecution takes place and the burden of proof lays the possecution. But there is an example where the onus is on the defendant to provide proof of innocence. I knew that there was but couldn't remember it until today. If you are charged with vat fruad and I think the same applies with money laundering it is up to you to provide evidence in your defence and as such you will be seen as guilty until you prove your innocence. I do not want to start the circle again, but the fact remains that defamation, libel and slaunder are expensive and complex cases.
Civil and criminal cases have a different burden of proof, but the onus of providing that proof remains the same. I have no experience of VAT fraud, but thinking through the scenario, I'd say that the accuser has made the positive assertion, and must have provided strong evidence to support their claim. The defendant then needs to make their own positive assertion to rebut the evidence, in doing so, they'll be the ones needing to prove the positive. It's still the same, it has to be as it's how logical argument works, and that's what the legal system is based upon.