In 2002 the United Kingdom passed the Proceeds of Crime Act, which allowed police to confiscate property obtained through unlawful conduct. The intention being to make it easier to deprive criminals of their ill gotten gains. Presumably the idea was that individual criminals would have their loot seized and that would serve as a lesson to the others that crime doesn't pay.

Things went somewhat awry when the Metropolitian Police launched Operation Rize, and seized the contents of over 6000 safe deposit boxes (from three locations, run by the same company), after getting a judge to sign off on it apparently with statistical evidence that 80-90% of the safe deposit boxes were suspicious. but in reality more like 10% have any connection to serious crime. So far -- approximately a year later -- more than 2000 of the legitimate box owners have managed to get their contents returned, some with considerable difficulty.

It appears the police are quite pleased that their fishing expedition uncovered an Aladin's Cave of ill gotten gains, despite the fact that only about 900 out of over 6000 warranted further investigation.

New Zealand police also have a financial crimes unit to enforce (inter alia) the new Criminal Proceeds (Recovery) Act 2009 (replacing the Proceeds of Crime Act 1992). And there are concerns that the powers may be misused. And it was passed despite concerns about it breaching the principles of the Bill of Rights (something possible under New Zealand law providing it is explicitly done by an Act of Parliament). (Interestingly it appears that even Sensible Sentencing were against (a version of) the Bill -- although they appear to believe it was too piecemeal.)

Presumably after the bad press in the UK, the New Zealand police will be less inclined to attempt to use their powers in such a wide spread fashion. Especially since their attempts to use their new anti-terrorism powers against Maori activists didn't go well (wikipedia).

But "innocent until proven guilty" and "freedom from unreasonable search and seizure" seem to be rather weakened these days.

(Thanks to unixronin for the mention of these raids)