A non-target species of shark was killed in a SMART drum line trial off Newcastle's coastline in February.
The 2.3 metre Common Blacktip Shark was caught off Nobbys beach at 12.58pm and February 16.
If a shark or other animal is caught on the drum line, it alerts a boat crew which then tags and releases the animal.
The shark died despite the contractor arriving within 11 minutes of the alert.
"The animal was hooked in the mouth but its stomach was everted into the buccal cavity when the contractor arrived, indicating a stress response from capture," a report on the trial said.
Ten SMART drum lines were deployed between Stockton and Merewether during the 19 day trial, which was part of research project to determine the best way to protect surfers and swimmers from shark attacks.
The drum lines were positioned 500 metres off the beach and consisted of two buoys and a satellite-linked communications unit attached to a hook baited with a single mullet.
A one metre Dusky Whaler, another non-target species, was caught at Stockton Beach 4.32pm on February 5.
The shark was found alive even though the SMART drumline failed to set off an alert when it was caught.
"The trigger was still intact and failed to dislodge. The shark was tagged and released immediately."
Drum lines are designed complement existing shark deterrents such as shark nets.
If a shark is one of three "target" species - white, bull and tiger - it is tagged then released a kilometre offshore.
Other marine animals caught on the drum lines are released immediately.
Supporters of SMART drum lines argue they compare favourably with traditional shark-meshing.
The meshing program killed more than half the 228 marine creatures entangled off Newcastle and the Central Coast in the 2017-18 season.
Only 21 of the animals caught were white, tiger or bull sharks.
The government has been trialing SMART drum lines off Ballina, Lennox Head and Evans Head for the past two years.
The Department of Primary Industries data shows the trial has caught 213 white sharks, 12 tiger sharks and nine bull sharks since December 2016.
One of the white sharks died before being released, and another was found dead on Airforce Beach, Evans Head, five days after being released.
The DPI says the north coast drum lines have caught 87 non-targeted animals, mostly hammerhead, blacktip and dusky whaler sharks. All were released alive except a black marlin and a blacktip shark.
A six-month trial at Coffs Harbour caught 16 white, 18 tiger and 18 non-target sharks, and another six-month trial at Forster caught 65 white, two tiger and 17 non-target sharks.