Brown denied the allegations, while the NFL opened its own investigation.
On Monday, Sports Illustrated ran a story from a second woman, who came forward on the condition of anonymity.
Antonio Brown faces a second allegation of sexual misconduct from a woman https://t.co/gzyONl643y— Sports Illustrated (@SInow) September 16, 2019
She claimed to have worked on a mural for Brown at his house in 2017 after he had been impressed by a portrait of the then Pittsburgh Steelers star.
The woman said Brown appeared behind her completely nude except for a washcloth covering his genitals.
She said she took this as a sexual advance but "kept [her] cool and kept painting" and subsequently never saw Brown again, opting not to press charges at the time.
Responding to the Sports Illustrated story, Darren Heitner, Brown's attorney, issued a firm denial on Twitter.
"Antonio Brown has reviewed the sexual misconduct allegations made by an unnamed artist included in a recently published Sports Illustrated article and denies that he ever engaged in such activities," Heitner said in a short statement.
"There will be no further comment at this time."
Antonio Brown has reviewed the sexual misconduct allegations made by an unnamed artist included in a recently published Sports Illustrated article and denies that he ever engaged in such activities. There will be no further comment at this time.— Darren Heitner (@DarrenHeitner) September 16, 2019
Brown has been at the centre of much controversy in recent months, having forced a trade from the Steelers to the Oakland Raiders, who then granted his request for a release after a series of off-field episodes.
The 31-year-old scored a touchdown against the Miami Dolphins on his Patriots debut on Sunday, finishing the game with four receptions for 56 yards.