Melania Trump has rejected suggestions that she violated visa rules when she started working as a model in New York.
In a statement, Mrs Trump - the wife of Republican presidential nominee Donald Trump - said she had followed immigration laws "at all times".
Mr Trump has taken a hard line on illegal immigration in his campaign.
Mrs Trump said she began working as a model in the US in 1996, but nude photos published last weekend by a New York tabloid appear to have been taken in 1995 in New York for a now-defunct French magazine.
Mrs Trump has yet to clarify what type of visa she used during the 1995 photo shoot.
So far, the Trump campaign has refused to say exactly which visas Mrs Trump had, and when she had them.
In a statement posted from her Twitter account, Mrs Trump said there had been "a lot of inaccurate reporting and misinformation" about her immigration status.
"I have at all times been in full compliance with the immigration laws of this country."
The owner of one modelling agency, Paolo Zampolli, said he sponsored Mrs Trump for an H1B work visa in 1996.
Mrs Trump has said that she had to go back to her native Slovenia every few months to renew her permit - something that was only generally necessary for tourist and business visas that did not permit work.
Among his hardline statements on immigration, Mr Trump has railed against the use of the H1B visa specifically, suggesting abuse of it was widespread and rampant.
The development comes during a turbulent week for the billionaire property developer, with reports of deep divisions in the Republican Party after a series of controversial statements by the nominee.