A visit by United States pop star Beyonce and rapper husband Jay-Z to Havana last week was a cultural trip that was fully licensed by the US Treasury Department, a source familiar with the itinerary said on Monday.

The longstanding US trade embargo against Cuba prevents most US citizens from traveling to the island without a license granted by the US government.

Three Cuban-American members of Congress, all Republicans from Miami and supporters of a firm stance on Cuba, have asked the Treasury Department to look into the licensing of the trip, prompting officials to seek more information from the organizers.

Beyonce and Jay-Z celebrated their fifth wedding anniversary in Havana and were greeted by big crowds as they strolled through the Cuban capital. The music industry power couple were instantly recognized as celebrities despite the past half-century of ideological conflict that separates the two countries.

The source said that the trip included visits with Cuban artists and musicians, as well as several nightclubs where live music was performed, and some of the city's best privately run restaurants, known as "paladares".

The visit was planned as a "people-to-people" cultural visit and involved no meetings with Cuban officials, or typical tourist activity such as trips to the beach, the source said. Even a walk around the Old City of Havana, mobbed by crowds of excited Cuban spectators, was led by Miguel Coyula, one of the city's leading architects.

Publicists for the couple did not return e-mails or phone calls seeking comment.

Beyonce and Jay-Z were the latest US stars, joining actors Bill Murray, Sean Penn and James Caan who have also visited the Caribbean island in the past few years. But the pair were the first to cause such a stir everywhere they went.

The couple arrived in Havana unannounced for a four-day visit on Wednesday on a flight from Miami. But word of their presence spread like wildfire, by text messaging and word of mouth.

Beyonce, who sang at US President Barack Obama's inauguration for his second term in January, was instantly recognized when she and Jay-Z, and their mothers, dined at La Guarida, the city's top privately run restaurant, on their first night.

The next day a crowd of several thousand people swarmed around them in Old Havana during a walk.

They also visited a children's theater group and several clubs where they heard live music, and occasionally took to the dance floor. On Friday, they toured Cuba's top art school and met with some young artists.

Govt propaganda

US Representatives Ileana Ros-Lehtinen and Mario Diaz-Balart questioned the couple's trip, saying it was being used for Cuban government propaganda.

Ros-Lehtinen, long a fierce critic of the Cuban government, said it was "very disconcerting that these two mega stars would go down to Cuba".

Florida Senator Marco Rubio said the Obama administration's cultural exchange programs "have been abused by tourists".

If the Treasury Department had licensed the trip "the Obama Administration should explain exactly how trips like these comply with US law and regulations governing travel to Cuba," Rubio said.

The Cuban government was unaware of the participants on the trip until shortly before they departed for Cuba, the source told Reuters.

Reuters