The brown jack (male trout) was caught on Saturday, March 11 in the Tongariro River in a mid-river pool. In true angling tradition, the name of the pool has remained undisclosed.
Aidan has been trying to catch one of the river's big browns for several years, and only the weekend before had broken his rod while trying to hook one of the elusive beasts.
Because it was Aidan's birthday, Chris bought him a nice new rod, a seven-weight Sage, and it was on the new rod, wet-lining with a woolly bugger fly that he had tied himself, that Aidan landed his fish.
The river was just starting to come up after a night of rain and was a little discoloured but Chris says Aidan knows where the fish lie and was able to drop the fly in the right spot.
The fish put up a good fight but Aidan eventually prevailed.
The experienced angler has been fishing for years and catches mostly rainbows that he normally releases, but this is the biggest fish he's ever caught.
"In the last 12 months he's been trying to target the browns so it's a good achievement. He reckons there's some bigger ones there too," Chris says.
Taupō trout guide Andrew Christmas said Aidan's trout was a big one for the Taupō fishery and came from a pool that "always produces nice fish".
"I've been a guide in Taupō for about 11 years and I haven't caught one that big yet and I do about 250 fishing days a year. It's a big fish for a wild fishery and an exceptional fish for Taupō."
The unofficial record for the largest brown trout caught on the Tongariro River was previously held by Mr Christmas himself, with a trout he caught last year that weighed just over 14lb (6.5kg).
"He's overtaken that, so it looks like I'm going to have to go fishing again," Mr Christmas joked.
"I'm very happy for him and it's great for the fishery."
DoC's acting fishery manager Dave Conley says while fish of up to 20lb (9kg) were seen in in the Tongariro River in the 1920s, Mr Wildey's catch was a "a very, very large fish" by modern standards, with most trout coming through DoC's fish trap averaging about four or five pounds (2kg).
"The fishery team was pretty gobsmacked by the size of it. It's a lovely fish and we'd be lucky to see one that size per year come out of the fishery, it's more of a two or three year event," he said.
He said the fishery was currently in good shape and had seen steady improvement over the last two or three seasons.
"Fish like that are pretty rare, they're rare to hook and even rarer to land because of the size of them and something certainly to skite about."