The US State Department is refusing to allow the daughter of Cuba’s President, Raul Castro, entry to visit Philadelphia in order to pick up an LGBT rights award.

She had been expected to attend a conference next week on civil rights for the LGBT community, sponsored by the Equality Forum, in the Pennsylvanian city.

Guillermo Suarez, spokesman for Cuba’s United Nations Mission, confirmed that Mariela Castro was in New York City on Thursday and had attended meetings related to the UN population conference in Cairo in 1994.

The State Department bars Cuban diplomats from travelling more than 25 miles from central Manhattan.

She is one of the experts designated by UN Secretary-General Ban Ki-moon to work on the 20-year follow-up to the action plan adopted in Egypt.

“That’s why she asked for the visa and it’s the reason for her presence in New York,” Mr Suarez said.

“We find it shocking that our State Department would deny freedom of speech, particularly at an international civil rights summit, to anyone, let alone the Cuban president’s daughter,” Equality Forum Executive Director Malcolm Lazin said on Thursday.

Mr Lazin added that Mariela Castro had agreed to speak on a panel about Cuba on 4 May and was to accept an award for her LGBT activism at a dinner in Philadelphia on the same night.

He did not expect any visa problems because she had been granted permission to attend an academic conference in San Francisco last year.

Mariela Castro, the niece of retired leader Fidel Castro, is director of Cuba’s National Centre for Sex Education. She has campaigned for same-sex marriage on the island.

State Department spokesman Noel Clay said he could not comment on the case because visa records are confidential.

The US has maintained a near total trade embargo against the communist country since 1960.