*The 7-year-old South African girl who has been living with Chris Rock and his now estranged wife since the age of 6 months has been in the U.S. with the help of a visitor visa, TMZ has learned.

As previously reported, the girl named Ntombi began living with Chris and Malaak Compton-Rock in 2008. Although there was no evidence of an official adoption, the Rocks treated her like a daughter, making her part of the family and enrolling her in school.

According to TMZ sources, Ntombi entered the country on a B2 “visitor for pleasure” visa:

The visa allows the visitor to stay in the U.S. for up to 1 year, after which time the visitor must go back to her country and fill out paperwork before coming back.

We’re told Ntombi and Malaak went back to South Africa every year and reconnected with the girl’s biological family, which included a mom, a dad, a brother and a sister. We’re told each time, Ntombi and Malaak returned to the U.S. in short order.

Sources connected with Chris say he has no idea if money ever changed hands from his family to Ntombi’s parents.