(CNN)Dug may not be the world's largest potato, but it's still pretty spudtacular.
When New Zealand couple Colin and Donna Craig-Brown first discovered the gigantic vegetable in their garden last August, they knew they had something special on their hands.
Dug is named for how the two of them unearthed it -- by digging.
They decided to submit Dug to Guinness World Records, and seven months and one DNA test later, they received some depressing news.
"Sadly the specimen is not a potato and is in fact the tuber of a type of gourd. For this reason we do unfortunately have to disqualify the application," a Guinness World Records spokesperson told the couple via email.
A tuber is an underground organic structure that stores water and helps plants regrow after winter or harsh weather, according to Amy Charkowski, professor and department head in the College of Agricultural Sciences at Colorado State University in Fort Collins.
Hamilton resident Colin Craig-Brown, 62, was surprised to hear the DNA results and quickly got to work unraveling the mystery. After pouring over the data results provided by Guinness World Records, he discovered that Dug came from a choko, a starchy plant in their garden that looks like a wrinkly, green pear.
Charkowski hypothesized, however, that Dug may actually be a tuberous root, a storage root similar to a potato tuber, but lacks buds like the eyes on a potato. A choko, also known as chayote, grows from tuberous roots, according to the Wisconsin Master Gardener.
He was initially surprised since he had tried a raw sample of Dug that tasted identical to a potato, but further research revealed chokos can have a similar flavor. The revelation came as a relief to Craig-Brown, because he was confused as to how a gourd could have gotten into that side of his garden.
"At least I answered all the questions and don't need to lay awake at 3 in the morning trying to figure out what has gone wrong with Mother Nature," he said.
Life above ground
A longtime gardener, Craig-Brown found Dug when he was tending to his plants and struck a hard object under the soil.
After pulling out the monstrous vegetable, he was "gobsmacked" at the size -- 7.9 kilograms (17.4 pounds), to be exact.
The current potato record-holder is Peter Glazebrook, a United Kingdom resident who grew a spud weighing 4.98 kilograms (11 pounds) in 2011.
A little trolley was built to cart Dug around, and the "potato" quickly became the talk of the town, Craig-Brown said.
A couple weeks into Dug's life above ground, Craig-Brown noticed it was spoiling so he stored the coveted veggie in his freezer.
Dug may have garnered thousands of admirers around the globe, but the vegetable's biggest fans are Craig-Brown's grandchildren, he said.
"I open up the freezer, take him out of the packing bags, set him down and their little eyes pop open and their chins drop," Craig-Brown said.
A future filled with potatoes
The world's heaviest potato award may still be on the horizon for Craig-Brown, even if it's not Dug.
"After getting ahold of all this scientific information, I'd at least give a crack at it myself," he said.
It won't be easy, though.
Multiple factors go into growing a giant potato that is at least 20 ounces (0.6 kilogram), according to Charkowski.
For optimal conditions, it should be a certified tuberous root of a russet variety that is free of disease, she said. The potatoes need to grow over a long season with cool nights no warmer than 85 degrees Fahrenheit (29.4 degrees Celsius).
Craig-Brown hasn't settled on what he's going to do with Dug now that the tuber has been disqualified, but he may try to memorialize it.
"I'm going to make a mold of him, so I've got a Dug lookalike that's nonperishable so that maybe my grandchildren's grandchildren can look at it and see what their granddad did," he said.