Havana, Cuba (CNN) -- Prominent Cuban dissident Oswaldo Paya Sardinas died in a car accident Sunday, his daughter Rosa Maria Paya told CNN. He was 60.
She said her father died after the car he was traveling in was struck by another car in Cuba's eastern Granma province.
The car crash took place at 1:50 p.m. near Bayamo, Cuba, according to statement released by the Cuban government's International Press Center.
Paya and passenger Harold Capero died in the accident, the statement said. Two other passengers -- a Spanish citizen and Swedish citizen -- were injured and taken to a hospital, it said.
The government statement says there was not a second car involved in the crash and said the rental car that Paya was traveling in lost control and crashed into a tree. Cuban police are investigating the crash, the statement said.
On Paya's website, his daughter Rosa Maria posted an audio clip saying his family believed that a second car had been involved and that it had intentionally struck the car in which Paya was traveling.
A devout Christian and an engineer, Paya was known far beyond Cuba for his criticisms of the island's socialist government.
In 2002, shortly before former U.S. President Jimmy Carter's visit to Cuba, Paya delivered petitions containing 11,020 signatures calling for democratic elections and freedom of speech to Cuba's National Assembly.
Although the initiative -- called the "Varela Project" -- was ignored by Cuba's government, Carter later spoke of Paya's signature drive during a speech that was broadcast on state television in Cuba.
The speech was the first time Cuba's government had allowed an American leader to address the populace as well as the first time that many Cubans had heard of Paya's efforts to change the country's political system.
Internal opponents to Cuba's government are routinely labeled as traitors by the state-run media.
In 2003, Paya received the European Parliament's Sakharov prize for freedom of expression. The award is named for Soviet dissident Andrei Sakharov and is awarded to those who work to promote human rights and democracy.