Two women have told the New York Times that Donald Trump touched them inappropriately, but the Republican candidate's campaign denies the report, the BBC reports on Thursday.
One woman said the White House hopeful grabbed her breasts and attempted to put his hand up her skirt on a flight three decades ago.
The second woman said Trump kissed her on the mouth against her will at Trump Towers in 2005.
Trump's campaign said "this entire article is fiction".
The New York Times was launching "a completely false, coordinated character assassination," a statement from his campaign said.
Jessica Leeds, 74, from Manhattan, told the paper she had been sitting next to Trump in the first-class cabin of a flight to New York when he lifted the armrest and began to touch her.
She was 38 years old at the time.
"He was like an octopus... his hands were everywhere," she said. "It was an assault."
Rachel Crooks was a 22-year-old receptionist at a real estate company in Trump Tower when she said she was kissed on the lips by Trump outside a lift in the building.
"It was so inappropriate," Crooks told the New York Times.
"I was so upset that he thought I was so insignificant that he could do that."
Neither women has ever reported their accounts to the authorities, but both shared what happened to them with friends and family.
Leeds said she was "angry and shook up" after Trump touched her.
She said she quickly left the first-class cabin and returned to economy.
Leeds said she had largely put the encounter out of her mind until last year, when Trump's presidential campaign took off.
"His behaviour is deep-seated in his character," she said. "To those who would vote for him, I would wish for them to reflect on this."
Crooks said she "started hysterically crying" to her boyfriend after Trump kissed her.
She said Trump later asked for her phone number, which he said he wanted to pass on to his modelling agency, but she never heard from them.
On coming forward, she said: "People should know... this behaviour is pervasive and it is real."
The Clinton campaign said the "disturbing" New York Times story "sadly fits everything we know about the way Donald Trump has treated women".
"These reports suggest that he lied on the debate stage and that the disgusting behaviour he bragged about in the tape is more than just words."