New questions surrounding Melania Trump's path to US citizenship have surfaced, with one attorney stating she received her green card in 2001 'based on marriage', four years before she wed Donald Trump.

Melania, a Slovenian-born model who worked in Paris and Milan before landing in New York, said she had never been married before she met the business tycoon.

But Michael Wildes, an immigration attorney who worked for Trump Organization 'on behalf of Trump models', alleges Melania was married before 2005, Univision reported.

A spokesperson for Trump shot down the shocking claims, telling Dailymail Online: 'Contrary to inaccurate reports today, Melania was not married prior to her marriage to Mr. Trump in 2005. She obtained a green card on her own.'

New questions surrounding Melania Trump's path to US citizenship have surfaced, with immigration attorney Michael Wildes stating she obtained a green card in 2001 'based on marriage', four years before she wed Donald Trump

Melania Trump issued a statement Thursday where she said she had been in 'full compliance' with the nation's immigration laws

Melania, who became a US citizen in 2006 after her marriage to Trump the year before, had obtained a green card in 2001 'based on marriage', Wildes said.

Wildes added: 'Before that, she had a work visa and was in full compliance on her visas and never disrespected any of them. That has been made clear to me.'

Michael Wildes worked as an immigration attorney for Trump Organization

The immigration attorney, who said he had been authorized by Trump Organization to speak about Melania, could not comment further on her status.

He told Univision: 'There are certain parts of the process that remain private. The immigration authorities don't discuss this nor should we.'

He also called the inquiry into Melania's immigration status 'moot and ridiculous'.

Wildes worked for Trump, ensuring competitors in the Miss Universe pageant obtained legal paperwork when the real estate magnate owned it.

Melania has faced media scrutiny surrounding her journey to the US as the wife of the GOP candidate - whose promises to crack down on illegal immigration have become central to his campaign.

His supporters regularly chant 'build the wall' at his rallies, referring to his plan to block Mexicans without proper documentation along the southern US border.

Italian businessman Paolo Zampolli said his agency Metropolitan Models sponsored Melania in 1996 with an H-1B work visa, which typically allows people to stay in the US for three years at a time, the Washington Post reported.

In March, the Donald said: 'The H-1B program is neither high-skilled nor immigration: these are temporary foreign workers, imported from abroad, for the explicit purpose of substituting for American workers at lower pay.

'I will end forever the use of H-1B as a cheap labor program, and institute an absolute requirement to hire American workers first.'

But Zampolli's account is inconsistent with Melania's statements in a January Harper's Bazaar interview.

In the interview, the former model said she would make frequent trips home to renew her visa - a move usually associated with a temporary business visa or a simple tourist visa.

Racy photos of Melania from 1995 also resurfaced in the New York Post this week, with Politico pointing out that they were taken in Manhattan a year before the former model claimed she came to the US.

Melania Trump took to Twitter on Thursday to push back at 'inaccurate reporting and misinformation' about her immigration status – which she has touted as part of the American Dream in interviews as well as her speech at the Republican Convention.

'Let me set the record straight: I have at all times been in full compliance with the immigration laws of this country. Period,' the Slovenian born model said on Twitter.

She continued: 'Any allegation to the contrary is simply untrue. In July 2006, I proudly became a US citizen. Over the past 20 years, I have been fortunate to live, work and raise a family in this great nation and I share my husband's love for our country.'

Melania Trump has appeared with her husband on the campaign trail, as she did in Waterloo, Iowa in February

She told Harpers magazine in July: 'It never crossed my mind to stay here without papers. That is just the person you are. You follow the rules. You follow the law.

'Every few months you need to fly back to Europe and stamp your visa. After a few visas, I applied for a green card and got it in 2001.'

She used similar language about required trips home in an interview with MSNBC, saying: 'I never thought to stay here without papers. I had visa. I travel every few months back to the country to Slovenia to stamp the visa.'

Paolo Zampolli, on Thursday told the Associated Press he got Melania Knauss her visa when he was a partner at the agency Metropolitan Models.

'She qualified. We got her the H-1B as soon as she came,' he said, mentioning the H-1B visa for 'fashion models of distinguished merit and ability.'

He said he used her work in Paris and Milan as the basis for the application. 'We used whatever she did before to get her a visa. She had enough tear sheets to qualify,' he said.

Melania Knauss married Donald Trump in 2005 at Mar-a-Lago in Florida.

Her website suddenly disappeared after questions were raised last month about her academic credentials.

Her official website, and her bio published by the Republican National Committee, stated that she earned 'a degree in design and architecture at University in Slovenia.'

CBS reported that she did not graduate and dropped out after a single year.