Justice Minister Judith Collins said the SFO believed "ad hoc changes" to its powers could have an adverse impact on its investigations.
"This is not desirable at a time when the SFO is investigating fraud in the collapse of several financial companies."
She said the act achieved "the right balance between the need for effective and modern search and surveillance powers and protecting the rights of citizens".
The production order regime formalised a common police practice of executing search warrants against people who were willing to assist. It avoided the need for police to enter the premises and to disrupt businesses or occupiers.
A new declaratory order regime recognised that criminals were finding new ways to evade detection. It would allow enforcement officers to ask the court to test a new technique or device or activity for its reasonableness before using it to investigate criminal activity.
She said journalists presented with an examination order or production order could refuse to answer questions or produce documents that would reveal the identity of their source.
In such cases where privilege was claimed and disputed by the enforcement office, the information or document could not be viewed by the officer until a High Court judge had decided that privilege should not apply.
Mana leader Hone Harawira said the bill was draconian and dangerous.
Instead of streamlining search and surveillance procedures it gave police powers to 70 Government agencies.