A former Playboy model involved in a custody battle has apparently jumped to her death with her seven-year-old son from the 25th floor of a New York hotel.

The pair checked into the penthouse suite of the Gotham Hotel in Manhattan at about 6pm on Thursday, police said.

They fell 23 floors and were found on a second-floor balcony at about 8.15am on Friday in the rear courtyard of the hotel, they said.

Law enforcement officials identified the woman as Stephanie Adams and her son as Vincent.

The officials said she was involved in a custody dispute over Vincent with her estranged husband, a Manhattan chiropractor named Charles Nicolai.

They said police had been called to their home several times in the past few months.

The New York Post profiled Ms Adams in 2013, saying that she had by then written more than 25 self-help books, ran an online beauty products company and managed the finances in her husband's office.

She appeared in Playboy in 2003, worked with Elite Model Management and had two business degrees, according to the profile.

"The stereotypes are sexist and unfair," Ms Adams said in the profile. "Just because I look a certain way and have expensive tastes, it doesn't mean I'm shallow.

"Style and looks don't mean lack of brains, sweetheart!"

Ms Adams and her husband were sued in 2013 by a massage therapist at the chiropractic office who claimed she was fired because Mr Nicolai said his wife could become jealous as the therapist was "too cute".

PA Media