Former MP John Banks says he may take legal action against Crown Law over what he says was misconduct in how it handled his case.
Mr Banks was convicted last August of failing to declare two $25,000 donations during his 2010 Auckland mayoralty campaign, as coming from internet businessman Kim Dotcom.
He appealed against that conviction after his wife found evidence proving that two American businessmen had attended the lunch on 5 June at which Mr Dotcom originally said the donations were discussed.
The Court of Appeal recently acquitted him of that charge, finding Crown Law had misled the court by failing to disclose a memorandum.
Attorney-General Chris Finlayson said today he was satisfied with the way Crown Law handled the case, saying an independent barrister handled most of the prosecution.
But Mr Banks said Crown Law spent more than 700 hours on the case, and the Solicitor-General Mike Heron himself conducted the appeal hearing.
He said he has requested all Crown Law documents and communication about his case, which may contain information that will allow him to pursue legal action.
The Crown had asked a barrister, Rowan Butler, to interview Mr Dotcom about the lunch and Mr Dotcom accepted the two Americans' evidence was correct.
However, he reverted to his original account, saying the lunch with Mr Banks occurred on 9 June, the same day the cheques were written.
Following that interview, Mr Butler provided a memorandum to the Crown saying Mr Dotcom changed his statements and that the donations were discussed at the second lunch.
However at the appeal hearing last October the Court was not told about Mr Dotcom's change of story.
The Court of Appeal judges said that had they known of Mr Butler's memorandum, they would not have ordered a retrial, and that the Crown's failure to disclose it had caused a miscarriage of justice.
The Court said it was satisfied the Crown's 'serious error of process' was an error of judgement rather than misconduct.
Mr Finlayson said he had taken a careful look at the Crown's actions and was satisfied with its conduct.
"Apart from limited involvement at various stages of the case, Crown Law briefed an independent barrister to conduct the prosecution.
"It did so for a number of reasons, including the involvement of Mr Dotcom as a witness and the politically controversial nature of the case.
"Because of the personalised nature of some of the allegations about the conduct of the Solicitor-General, I state for the record that he has my full confidence. He is an outstanding Solicitor-General."
Mr Finlayson said the next step in this case would be the determination of costs, which is a matter for Crown Law and Mr Banks' lawyer.