The Ministry for Primary Industries is reminding people of the rules around using set nets, after a shark washed up dead on a Nelson beach.
The young bronze whaler was found on Tahunanui Beach at the weekend.
A member of the public commenting online claims to have seen a person reeling in the shark trapped in a set net, who then released it.
The ministry's chief compliance officer for Nelson-Marlborough says restrictions apply to their use.
Anthony Little said along with the size and placement of a set net, they have to be marked with the user's name, and cannot be used in a way that traps fish on a falling tide.
"They can't be more than 60 metres in length, they can't be set within 60 metres of another net, they have to have floats that are clearly marked with the initial and surname of the person using them, only one net can be used from a vessel and they can't be used in a way that causes fish to be caught by a falling tide."
Mr Little said set nets were also used from beaches. He said there was no evidence of any increase in breaches of the rules.
"People have been using set nets for a long time and every year we do have breaches.
"At that this time of the year there are a lot of nets being used in the shallows and off beaches where I suppose people don't have access to a vessel."
People were also fishing for snapper at this time of year.
MPI does daily patrols at this time of year to check for any rule-breakers, and to educate people on the correct use of all types of fishing gear, Mr Little said.
He said the death of the shark washed up at the weekend has raised their interest, and they would be keen to talk to the person involved, but no offence had been committed.
Fisheries impacts on sharks are managed by the Ministry for Primary Industries under the National Plan of Action Sharks (NPOA Sharks). Rig, school shark, spiny dogfish, blue shark, porbeagle, mako shark, elephantfish, rough skate and smooth skate are managed under the quota management system.
Mr Little said there were more long-lines used than nets, but nets left overnight caused problems, which was a focus of their education.
"People need to use them more sustainably and that means staying with them, checking them often...because if you set one overnight and leave it, you come back in the morning and you don't know what you've caught."