Some of the models can be seen singing the lyrics: "Hit the store, I can get 'em both, I don't wanna choose, and I'm quick, cut a n***a off, so don't get comfortable".
The clip is believed to have come from one of Kloss's video blogs posted on her YouTube channel where it is shown at around three minutes in - though the part where the N-word is sung is not included.
From the video, it's unclear exactly which models said the word and which didn't.
The audio is not totally clear but it looks as if a room of models, including Karlie Kloss and Ming Xi, are rapping line-for-line Cardi B's song. Cardi B did not respond to the video but did retweet one person who wrote, "All these bitches said nigga, too". The footage, although inconspicuous, was slammed after people heard many non-black models seemingly rapping the n-word along with the song's lyrics.
The problem? In a room almost devoid of black models, you can hear them clearly singing the word "nigga" in Cardi B's line: "I don't wanna choose/And I'm quick, cut a nigga off, so don't get comfortable".
Wenger sends message to Arsenal fans after 1-0 win over Burnley
Arsene Wenger believes Arsenal will proceed with a renewed sense of confidence following their late 1-0 victory at Burnley . But an improved display after the interval resulted in what Wenger felt was a warranted second away win of the campaign.
His outrage is shared, and some people have called for the models to be fired.
Fans know exactly what they said, and it's not OK. They all gotta go'.
At this time, the video is still live and none of the models involved have commented.
Cardi B is fighting off criticism caused by a viral video which shows her flaunting her boobs.
It comes after Gigi Hadid announced she was not going to walk in the show in Shanghai earlier this month after she came under fire in China over a controversial video showing her squinting her eyes to imitate Buddha.