Waikato farmer Campbell Montgomerie (27) and English tourist Hannah Timings (28) disappeared in January 2004 when a Hughes 500 369HS helicopter crashed in the Hollyford Valley.
The wreckage was finally located on Wednesday evening near Humboldt Creek when a pilot on a commercial flight "spotted something out of place".
The remains are yet to be formally identified, which police said would be by DNA analysis.
Mr Montgomerie's parents, Ian and Elizabeth, arrived in Te Anau from Auckland yesterday after being notified by police.
They declined to talk to media.
Last night, the Otago Daily Times tried to contact Ms Timings' father, Phil, in Cheltenham, England. A family friend said Mr Timings was out, but would be unlikely to comment.
Mr Montgomerie and Ms Timings were flying from the Routeburn Track to Milford Sound on January 4, 2004, when radio contact with the Milford radio tower was lost. The helicopter had plunged into inaccessible terrain in the Humboldt Mountains. Despite a six-day search, their bodies and the aircraft were not located.
Glacier Southern Lakes Helicopters chief executive and pilot Pat West was one of four who visited the site on Wednesday after a company pilot, Brendan Hiatt, discovered the wreckage while on a commercial flight between Fiordland and Queenstown.
"He was on his way back from Milford Sound on a commercial job and spotted something out of place," Mr West said.
Mr Hiatt hovered above the wreckage to identify what he had initially thought was crash wreckage and he identified the tail section of the Hughes 369 HS.
The pilot flew his four passengers back to Queenstown, then returned to the crash site with Mr West and two Queenstown police officers.
Vegetation in the area was thick and the wreckage was lying on the south side of a rock face, which would have made it nearly impossible for the initial searchers to locate the helicopter, Mr West said.
"Because the helicopter is a dark green, it is hard to see through the alpine scrub.
"We were [just] at the right altitude, at the right place at the right time [to spot a reflection]."
The wreckage covered a sizeable area, with parts of the aircraft scattered across the rock.
"It will hopefully give the families some closure and put the mystery to bed."
The 2004 police search covered the various routes the helicopter might have taken from Lake Howden to Milford Sound and included more than 200 flying hours and 2500 people hours.
In a statement yesterday, police said the wreckage was found at the extremities of the original search area, which comprised extraordinarily difficult and complex terrain.
In August 2004, coroner John Donaldson said the crash was likely to be the result of an error of judgement by Mr Montgomerie, who was unfamiliar with the area and conditions.
Seven specialist police staff and two alpine cliff rescue team members were flown to the area yesterday to examine the site.