Australian-born Miss Otago Monique Cooley assumed she qualified for Miss New Zealand automatically after living here for 12 years.
The Queenstown 22-year-old has been dragged into a beauty contest citizenship row after it was revealed newly crowned Miss Universe New Zealand Avianca Bohm may be stripped of her tiara because she is a South African.
Organisers today revealed Miss Cooley, the third runner up, was also ineligible for the crown because she is an Australian.
The beauty therapist told the Otago Daily Times she only found out about her possible ineligibility for the prize when her friend called her up and alerted her it had been in the news.
"I have never applied for it [citizenship], I assumed it was automatic. I have been living here for 12 years so I consider myself a New Zealand citizen.
Miss Cooley, who was born in Adelaide in 1990, moved to New Zealand when she was ten years old and did not realise she had to apply for citizenship.
She said she would be applying for citizenship as soon as she could, even if it meant doing some more paperwork while she was on holiday with her mother in Hawaii.
The pair flew out from Auckland at midday.
Meanwhile, unless the citizenship of South African-born Avianca Bohm is fast-tracked she is unlikely to be able to attend Donald Trump's Miss Universe pageant later this year.
Representing Howick, the 22-year-old was crowned in a ceremony on Saturday night in Wellington.
But less than 24 hours later, organisers admitted she should never have won.
Pageant director Val Lott blamed the judges and said they were told Ms Bohm was not eligible to win.
"It's not embarrassing for the competition. It's embarrassing for the [chief] judge, who should have taken on board what I said to him.
"It says that in their entry form. [Ms Bohm] and I both had a clear understanding that she couldn't win.
"I said, you can enter it because it will still be a lot of confidence-boosting and great for your area to represent Howick.''
Ms Lott has contacted organisers of Miss Universe 2012 to ask if Ms Bohm can represent New Zealand as a permanent resident.
The judging panel was headed by Jack Yan, publisher of fashion magazine Lucire.
Mr Yan told the Herald he disputed Ms Lott's version of events, but said he didn't want to get into a game of "he said, she said''.
"If I do that, it's going to drag on with no end. I think we need to look to the future and see what the next right step is.''
Another person involved in the competition, who asked not to be identified, pointed to an online casting call which said that to enter, "you must have NZ residency and citizenship''.
However, the Herald understands some of the other contestants also don't hold citizenship.
Contestants must pay a "sponsorship fee'' of $3000.
Yesterday, Ms Bohm, who recently graduated with a fashion qualification, said she was sure her citizenship would be fast-tracked.
"Everyone's got contacts, and it's one of the first things that we're going to do and sort out.
"It's just the paperwork. I mean New Zealand is such a multicultural country ... It's not an issue to me at all, I'm not even worried about that.''
Ms Bohm moved from Pretoria to Auckland aged 16 and had to learn English as her second language, having spoken only Afrikaans until then.
She said she now considered herself a Kiwi and would make her future here.
"I'm so, so, so excited to meet Donald Trump, and to meet all the other girls from all the other countries.''
Miss Universe 2012 is to be held in December, with pageant owner Donald Trump yet to make a final decision on the venue.
New Zealand's runner-up, Miss North Harbour Talia Bennett, 23, last night referred all questions to Ms Lott.
It is not the first time the pageant has attracted controversy.
In 2008, tertiary workers took issue with Massey University publicising a science graduate's third place in the pageant on its website.
The Association of University Staff said the piece, which included a bikini picture, was "one of the most banal news features emanating from a university this year''.
The same year, Miss Universe New Zealand Samantha Powell poked out her tongue while performing a haka in the lead-up to the event in Vietnam.
The action is meant to be performed only by men, and Ms Powell was criticised by the then Miss World New Zealand, Kahurangi Taylor - the winner of a rival pageant.
- Nicholas Jones, New Zealand Herald