An orthodox application of Hunter v Chief Constable of the West Midlands Police  AC 529 (HL), prohibiting the use of civil proceedings to mount a collateral attack on a decision in a criminal case, is Hurnam v Bholah (Mauritius)  UKPC 12 (12 July 2010).
Issues that have been decided to have reached the standard of beyond reasonable doubt cannot be taken to be capable of having a different outcome if they were to be decided on the balance of probabilities. The exception is where fresh evidence passes a "rigorous test" (per Lord Diplock in Hunter at 545).
In Hunter, the Birmingham Six case, the accused were held beyond reasonable doubt at voir dire not to have been subjected to violence before they made statements which were therefore admissible at trial, so subsequent civil proceedings by the accused against the officials for alleged assault were stayed as an abuse of process.
Ultimately the Birmingham Six were shown to have been wrongly convicted – even wrongly accused – and they received compensation.
An interesting aspect of Hurnam v Bholah is its reference (37-38) to French law on issue estoppel. In Mauritius the substantive law is based mainly on the French Napoleonic Code, whereas procedural law is mainly English. In English common law the position was that neither an acquittal nor a conviction was admissible on the same issue in civil proceedings: Hollington v F Hewthorn & Co Ltd  KB 587. This was the applicable law in Mauritius. The position in the UK was changed by statute (s 11 Civil Evidence Act 1968) so that a conviction is prima facie evidence in civil proceedings that the person did commit the offence. But French law permits the results of criminal cases, whether convictions or acquittals, to be used in evidence in civil cases. However this has been held not to be part of the procedural law of Mauritius.
There is an obvious irony in Hunter being authority for preventing civil proceedings being used to undermine a criminal conviction, as the convictions there were unsound. But the point is that a conviction is a matter of criminal law and it can only be challenged on appeal or on prerogative review.
In the present case the Board held (31) that Mr Hurnam was seeking to use civil proceedings, not to obtain damages, but to restore his reputation by calling into question the guilty verdict in the criminal proceedings. He had been found guilty of conspiring to fabricate an alibi, and his civil proceedings claimed that the allegation that he had conspired to fabricate the alibi was false.
Lord Brown agreed with the judgment of the Board delivered by Lord Rodger, and added that witness immunity protected the witness whose evidence supported the allegation of conspiracy to fabricate the alibi from subsequent suit (Darker v Chief Constable of the West Midlands Police  1 AC 435), the policy being that witnesses should not, for fear of being sued for something they say, be afraid to tell the truth (citing Lord Hoffman in Taylor v Director of the Serious Fraud Office  2 AC 177, 208). There was no issue of witness immunity in Hunter and Lord Brown considered that Hunter was a weaker case for striking out than was the present case.