The damage to Rudd's reputation, especially at this age and stage of his life and career, had been significant - on a global scale, he said.
"We are looking into what appears to be inept and irresponsible policing practices," Mr Tuck said.
He said a team of international lawyers are working to ascertain the extent of damages and appropriate reparation and relief to Rudd's 40-year career.
Police said the decision to withdraw the charge was made by the Crown solicitor.
Police declined to comment further, as the matter was before the court.
Rudd remains on bail at his waterfront mansion.
He is due back in the Tauranga District Court in February for a case review hearing on the threatening to kill charge, as well as possession of 130 grams of cannabis and 0.7g of methamphetamine.
Rudd has denied the criminal offences and the case is likely to be defended at a judge-alone trial.