"We didn't really realise how big it was," Turk said.
"As it came in, Mark said, 'oh my god, it's a horse'."
Turk, who grew up in Rotorua, lives in Auckland but still makes the trip to Rotorua to fish with friends.
Apart from occasionally taking a catch home to eat, Turk said he preferred to catch and release his fish.
But this one was different - "it's one of those fish in a lifetime and you don't know when it will come again".
Turk said the last big trout he caught were a few 10-pounders in the 1990s.
Turk took his catch to local trout and game bird taxidermist Ray Port who had been in the business for 40 years.
Port said the number of trophy trout brought to him was not as large as it used to be.
"A few have come in since Christmas, but compared to 10, 15 years ago, that's nothing."
Fish & Game officer Mark Sherburn said Lake Rotorua was a natural fishery, with peaks and troughs to be expected.
The fish had previously been on display in a large pond at the hatchery but were released while the hatchery was repaired.
Sherburn said none of the trout released were breeding fish.
"We dropped them into Lake Rotorua hoping anglers would be able to catch a few of them so we are rapt several have been landed already".
Sherburn said wild trout usually weigh 1.2kg and have cleaner fins while those released would have slightly damaged fins and could weigh up to five times as much.
Fish & Game rangers weighed a rainbow trout caught from the Awahou Stream mouth which tipped the scales at 5.5kg and have received feedback from several others about trout "much bigger than normally found" in Lake Rotorua.
Fish and Game said the fish were likely to stay in the cooler area of inflowing Rotorua Steams and more could be expected to be caught over summer.