The federal R. Kelly investigations are expanding — agents specializing in human trafficking cases have now reached out to Kelly’s former stylist, who has ties to a couple of the singer’s exes.

Sources close to celebrity stylist Kash Howard tell TMZ … Dept. of Homeland Security agents contacted Kash Wednesday and wanted to schedule a sit-down with her. It appears the call was prompted by a video that popped up all over YouTube this week.

In the video, Kash is behind the wheel of a car with 2 of Kelly’s ex-girlfriends, Halle Calhoun and Vonecia Andrews, as they talk to a media outlet about their relationships with the singer. Vonecia, aka Vee, was sobbing throughout the video, which our sources say Kash recorded last year.