A maximum fine of $250,000 could be issued to suspects for illegal fishing in Northland.
A man and a woman in their 40s have been questioned by the Fishery Officers.
The Ministry for Primary Industries searched their Tikipunga residence following their investigation which found illegal sales of crayfish on Facebook, ranging between $20 and $30 each.
Four Whangārei men were also apprehended for excess toheroa.
474 toheroa were taken from Ripiro Beach on Dargaville's west coast.
Under law, toheroa can only be gathered by way of customary permit for hui or tangi.
All of the suspects will be prosecuted under the Fisheries Act.