MPI and Sanford have been contacted for comment.
On Tuesday, the Government committed to speeding up the rollout of onboard cameras on New Zealand's commercial fishing fleet, which are used to detect any illegal activity.
However, the MPI's lawyers have raised doubts about whether the video footage could actually be used to prosecute fishers.
As a result, Primary Industries Minister Nathan Guy said an amendment to the Fisheries Act could be required "to ensure that we can use these cameras for compliance reasons".
The problem became apparent last week when a 2013 Ministry for Primary Industries investigation called Operation Achilles was leaked to the public.
It showed that five fishing vessels were caught on camera dumping large amounts of healthy fish off the coast of the South Island, but no prosecutions were taken.
The ministry has launched a QC-led review of the Operation Achilles investigation, including the decision not to prosecute any of the fishers.
Operation Achilles also showed that two Hector's Dolphins -- a relative of the Maui's Dolphin -- were caught by one of the vessels. One of the dolphin deaths was not reported.
Sanford has been named in MPI reports, subsequently leaked to Newshub. In one, a fishing investigator inspected two Sanford vessels and said the weight of the catch was "understated" using a system that was "inherently biased".
There was no prosecution or penalty. Sanford says it operates with integrity, and complied fully with all aspects of the investigation.
Trident chief executive David Middleton said the company was a limited partnership of 14 companies that own New Zealand fisheries quota, and have chosen to invest in research and development to maintain the long-term value of their quotas.
"Trident Systems is contracted to gather specific observational data from the footage, while MPI also has access to the footage. This, together with the fact that science information designed for fisheries management must be assessed via the peer review process defined by the research and science information standard for New Zealand fisheries, provides assurance of the integrity and quality of the information derived from the programme."
Sanford chief executive Volker Kuntzsch said Greenpeace should support and not attack the industry, as it was investing to "ensure we have the best technology, monitoring and research available on our fisheries".
"The industry partnerships with Trident are no secret, they are on the Trident website.
We are proud of that work, this technology on our boats and the investment we are making, which we have been talking about for the past year.
"I'm sure I speak for everyone involved in investing in the Trident electronic monitoring technology and research, when I say that we would be very pleased to host Mr Norman to get him fully briefed on this technology, what it does, and why we're backing it."
Steve Halley, MPI's manager of inshore fisheries, said Trident was successful in the open tender for the installation of cameras on the Snapper 1 trawl fleet.
"MPI has full access to the footage obtained in the trial and will review footage to ensure compliance...there are rigorous standards in place to test the electronic monitoring including MPI independent observers on some vessels operating alongside the cameras. The results of the trial will be subject to expert scientific review as part of a programme of a technology development programme."
Mr Halley said a decision on who would deliver technology for a wider surveillance programme was yet to be made.
"This will be based on an open tender process. Combined with new legislation and increased observer coverage it will provide a state of the art fisheries management system. Regardless of what organisation wins this open tender it will still be administered exclusively by MPI staff. That includes reviewing footage and undertaking resulting compliance work."