The opposition Christian Liberation Movement called Monday for an independent investigation to be carried out in the death of the group's leader, Oswaldo Paya, in a traffic accident one year ago.

Paya, 60, died July 22, 2012, while traveling from Havana to the eastern city of Santiago de Cuba.

Angel Carromero, a leader of the youth wing of Spain's governing Popular Party, was at the wheel of the rental car that crashed with Paya, fellow dissident Harold Cepero and Swedish political activist Jens Aron Modig aboard.

Paya and Cepero were killed in the accident, which Cuban authorities attributed to excessive speed, but Paya's family and the movement he founded, known by the Spanish initials MCL, reject the official account.

"With the passage of a year since the provoked deaths of Harold Cepero Escalante, an MCL activist, and Oswaldo Paya Sardiñas, our National Coordinator, we once more request an independent investigation to clarify and make public the truth about the facts," the movement said Monday in a statement.

The 27-year-old Carromero was convicted in Cuba of negligent homicide and sentenced to four years in prison, but he returned to Madrid last December under a 1998 bilateral accord that allows convicts to serve their sentences in their homelands.

Besides calling for an independent probe of Paya's death, the MCL is demanding the holding of a plebiscite that "allows Cubans to decide the course of their present and future as a nation."

Paya was the driving force behind the Varela Project, according to which he proposed a referendum for a democratic and peaceful transition on the island and in 2002 presented thousands of signatures supporting that idea to the Cuban Parliament.

That same year, Paya became the first Cuban dissident to receive the European Union's Sakharov Prize in recognition of his work to foster a transition to democracy in Cuba. EFE