O'Connor said MPI officers could go on to a property, but not a house or a marae "just to simply inspect - not to search."
Listen below:
Mackay points out that inspect and search are similar terms.
"All this power does is give MPI the ability - if they see something that they believe is relevant and confirms non-compliance they can lawfully seize it."
"They can not go into your house without a warrant."
Addressing recent criticism of the changes, O'Connor said the Bill was passed with urgency and did not go through a select committee because the changes were, "minor technical issues to bring it into line with other law" .
"There are bigger issues in NAIT that we will bring back in a new piece of legislation. It will go through select committee, it will be debated and we'll take it through the house."
O'Connor blamed the previous government for the current situation with the Bill.
"If the National Government had done its job in the first place and aligned the NAIT legislation with search and surveillance which they said they were going to do ... we wouldn't have to make these technical changes now."
He said farmers were confused by the NAIT changes because of media repeating the Opposition's opinion about the Bill changes rather than reporting a "detailed investigation."
Also in today's interview: Damien O'Connor gives an update on the Mycoplasma bovis response.