Acting prosecutions head Mokotedi Mpshe has been accused of unethically plagiarising a Hong Kong judge while explaining why he was dropping the criminal charges against ANC president Jacob Zuma.

James Myburgh, editor of the popular website politicsweb.co.za, says he has established that large tracts of Mpshe's lengthy explanation were word-for-word copies of a judgment handed down by Justice Conrad Seagroatt of the Hong Kong High Court on December 13 2002.

"Most strikingly of all are Justice Seagrott's concluding remarks. These seem to presage by some six-and-a-half years - almost to the word - the Mpshe comments," Myburgh said.

"It is against this evolved statement of broad principle," Seagrott wrote, "that the prosecution's failures and shortcomings with regard to disclosure must be seen and tested. Those for close consideration are best summed up by such expressions as 'so gravely wrong', 'gross neglect of the elementary principles of fairness', 'so unfair and wrong', 'misusing or manipulating the process of the court'. If those failures can properly be so categorised, are they such as to make it unconscionable that a re-trial should go forward?"

Myburgh commented: "It is rather remarkable how Mpshe's opinion of McCarthy so closely resembles that of Justice Seagrott's opinion of the prosecution in his case in Hong Kong. Their conclusions are rather similar as well.

"Mpshe presented an argument which he said formed the legal basis for the decision. But it now turns out that he was rehashing a judgment presented in Hong Kong six years ago, which itself was overturned on appeal. So what relevance can the case have for Mpshe's legal grounds for his decision?" Myburg asked.

Myburgh reported that one section of Seagrott's judgment was headed "The abuse of process - the perennial dilemma". Myburgh said: "It - rather strikingly - cites all the British Commonwealth judgments that Mpshe's statement referred to. Even more strikingly the phrases quoted are almost all the same as well - give or take some self-serving summarising, truncation and rewriting by the NPA.

"There are a number of questions that one could ask about this," Myburgh said. "Are, for instance, these rulings really relevant to Mpshe's decision to drop charges? This is not just because South Africa has its own common law and constitution, but because these judgments all discuss the considerations that the courts should weigh up when asked to stay proceedings. One would not know this from Mpshe's decision as most references to 'the court' have been excised and replaced with phrases such as the 'criminal justice process'. However, the really interesting question is where this all comes from."

The DA is challenging Mpshe's decision to drop Zuma's charges on the basis that he did not have legal grounds for doing so.