HAVANA — Samantha Powers, U.S. ambassador to the United Nations, has called for an investigation into the death of Catholic Cuban dissident Oswaldo Payá, the founder of the Christian Liberation Movement, who died in Cuba last year under mysterious circumstances.

Diplomatic sources said Ambassador Power spoke with the Cuban chancellor, Bruno Rodriguez, during a lunch hosted on Tuesday by Argentine President Cristina Fernandez for the delegations that took part in the U.N. Security Council debate.

News of Power's conversation with Rodriguez follows claims by Spanish political operative Ángel Carromero that Paya was deliberately killed by Cuban secret service agents rather than in an accidental car crash with Carromero at the wheel.

Payá's Christian Liberation Movement called for non-violent protest and democratic reforms against the Communist Party in Cuba. He was 60 years old when it was reported he had died on July 22, 2012, in a car crash that authorities ruled was an accident where Carromero was at fault.

In an interview published by the newspaper El Mundo, Carromero said that he had been in a car with Payá when another vehicle began to follow and harass them. The vehicle, which Payá identified as belonging to the Communists, then began to ram them from behind and forced them off the road.

Claims that Payá died in a car accident were “the perfect alibi to cover up the death of the only opposition figure that could have led the transition in Cuba,” Carromero said.

Carromero was found guilty of vehicular manslaughter in the deaths of Payá and fellow dissident Harold Cepero by a Cuban court in October 2012. He has been serving out his four-year sentence in Spain under varying restrictions.

Rosa Maria Payá, the slain Catholic leader's daughter, expressed gratitude over the news of the ambassador’s conversation with Rodriguez in a post on her Twitter account.

“Thank you, Ambassador Power, for your words to the Cuban foreign minister. The U.N. can help to put an end to the impunity of the Cuban government,” she said.

In statements to Diario Las Americas, Payá said there is will in the Cuban government to clarify the facts surrounding the death of her father. She said evidence exists that contradicts the official version of events, including testimony from eyewitnesses and from nurses at the hospital where the crash victims were taken.

She also said the government never provided her family with results from the autopsy performed on her father, despite their repeated requests and the fact that such results are usually provided to families within a month.

More than 100 world leaders recently marked the first anniversary of Oswaldo Payá's death by joining together to call on the United Nations to carry out an independent and international investigation.

Rosa Payá said, “We trust that a serious investigation will be opened, but we understand that it is a long process that could take several months.”