Beyoncé and Jay-Z stirred controversy recently after the couple was spotted celebrating their fifth wedding anniversary in Cuba - a country that is forbidden to US tourists.
The Associated Press reported that two Cuban-American US Congress representatives wrote the Treasury Department asking for information on the couple's trip.
American citizens are not allowed to go to Cuba for tourism but many travel via Canada or Mexico to make the trip.
Special visas for religious or journalistic purposes are required for American visitors to the island.
Reps. Ileana Ros-Lehtinen and Mario Diaz-Balart from south Florida asked for information on the type of visa the couple traveled on.
The letter read: “We write to express concern and to request information regarding the highly publicized trip by U.S. musicians Beyoncé Knowles-Carter (Beyoncé) and Shawn Carter (Jay-Z) to Cuba. We would like to respectfully request, within all applicable rules and guidelines, information regarding the type of license that Beyoncé and Jay-Z received, for what purpose, and who approved such travel.”
Visiting Cuba, upon which the US has had a decades-long embargo, can land someone in prison for up to 10-years and a $250,000 fine.
Jay-Z and Beyoncé's trip last week was unexpected and the couple did not comment afterwards.
Both had to be protected by Cuban police from throngs of people who came to see the two stars outside their hotel in the nation's capital.