An Elle magazine advice columnist who is suing Donald Trump for defamation for denying he raped her approximately 24 years ago wants the US president to provide a DNA sample to see if he came into contact with the dress she said she wore.

A legal notice, seen by Reuters and verified by lawyers for the columnist E Jean Carroll, was dated Thursday and expected to be filed with the New York State Supreme Court in Manhattan.

It asks that Trump be required to submit to a physical examination on March 2, perhaps in Washington, to obtain a sample from his cheek, blood or skin cells for DNA analysis and comparison against "unidentified male DNA" on the dress that it said Carroll wore.

Lawyers for Trump did not immediately respond to requests for comment. Trump has denied knowing Carroll and the alleged encounter.

The notice said several other people, whose names were blacked out in a lab report also seen by Reuters, had been tested and eliminated as possible "contributors" to DNA found on Carroll's Donna Karan dress.

In a New York magazine article last June and her memoir published the next month, Carroll accused Trump of raping her in a dressing room at Bergdorf Goodman in midtown Manhattan, between the autumn of 1995 and spring of 1996.

Carroll sued over statements Trump later made, when he said he did not know her and that she was "totally lying" in order to boost book sales.

Trump also told The Hill newspaper that Carroll was "not my type" and the alleged encounter "never happened."

Carroll's lawyer Roberta Kaplan in a statement called it "standard operating procedure in these circumstances" to obtain DNA samples from accused people.

Trump's lawyers may nonetheless ask the New York state judge overseeing the defamation case not to require a sample.

The judge earlier this month rejected Trump's effort to dismiss the lawsuit altogether on jurisdictional grounds.

In a statement on Thursday, Carroll said that since the alleged encounter with Trump, she had worn the dress only at a photoshoot for the New York article.

Bill Clinton underwent DNA testing during independent counsel Kenneth Starr's 1998 probe into the then-president's relationship with White House intern Monica Lewinsky.

Clinton later admitted to having had an inappropriate relationship with Lewinsky. He was impeached over the scandal in December 1998 and later acquitted in the US Senate.

Starr is defending Trump in the president's current impeachment trial.

- Reuters