Jay-Z and Beyonce's trip to Havana to celebrate their fifth wedding anniversary last week drew vast crowds of Cuban fans. Now it has also drawn the attention of US congress.
Two congressmen have demanded to know whether their visit broke the rules of the US economic embargo.
Under a 51-year law, Americans cannot travel to the Communist island nation without express permission from the US government.
Ileana Ros-Lehtinen and Mario Diaz-Balart, two Republicans whose Florida districts have large Cuban-American populations, have questioned whether the couple obtained permits.
They have written to the director of the US Office of Foreign Assets Control to seek "information regarding the type of licence that Beyonce and Jay-Z received".