MANILA: A gripping documentary about a wealthy, young man sentenced to death for the rape and murder of two sisters has catalysed a movement to expose wrongful convictions in the Philippines.

The award-winning 'Give Up Tomorrow' follows Francisco Juan Larranaga as he is transformed from a carefree, culinary art student into one of the nation's most vilified and hated people whose adult life is lost behind bars.

The documentary presents a compelling case that corrupt authorities framed Larranaga, aged 19 then, and six other young men for the 1997 rape and murder of the two sisters in the central Philippine city of Cebu.

“This was a systematic failure of the justice system, and of society,” the producer of the film, Marty Syjuco, who is related by marriage to Larranaga, told AFP following a screening of the movie in the Philippines recently.

“He didn't stand a chance from day one. There was no presumption of innocence. From the time he was arrested and paraded for the media he was already judged guilty by the public.” The killings of Jacqueline and Marijoy Chiong, aged 23 and 21, in the central Philippine city of Cebu triggered public outrage across the Catholic nation.

With enormous political pressure for authorities to quickly resolve the case, police accused Larranaga of being the ring-leader of a gang that abducted, raped and killed the Chiongs.

However dozens of witnesses said Larranaga was in Manila, the nation's capital, 550 kilometres (340 miles) away, at the time of the abductions and murders. He always maintained he had never before met his co-accused.

The documentary shows how the nation's media accepted the police account as fact and incited hatred against Larranaga, a member of a rich Filipino-Spanish family who had earlier been placed on a police watchlist for minor crimes.

After months of emotionally charged hearings that the UN Human Rights Commission would later describe as an ‘unfair’ trial, the judge presiding over the case found the seven guilty.

Larranaga and the others appealed the conviction. But the country's highest judicial body, the Supreme Court, instead raised their life sentences to death by lethal injection.

Throughout the ordeal, Larranaga maintained his innocence and the documentary which is filmed over seven years, shows a young man maintaining a sense of dignity while growing up in some of the nation's most infamous prisons.

The film is named after the phrase Larranaga repeats to himself, “give up tomorrow”, whenever he comes close to despair.

The Larranaga family filed a complaint with the UN Human Rights Commission, which in 2006 ruled that he had been denied due process and cited multiple incidents of major flaws in the case against him.

It called for the government to commute his death sentence and grant him early release on parole. Fair Trials International and the Spanish government also pressured the Philippine government on behalf of Larranaga.

After nine years in jail, Larranaga's first apparent piece of luck occurred later in 2006 when the Philippines abolished the death penalty.

Larranaga was then extradited to Spain in 2009. But, according to the documentary, authorities there would only reduce his sentence and release him on parole if he admitted his guilt.

The documentary ends with Larranaga saying he would not admit to something he had never done, even if it meant he had to spend the rest of his life in jail.

While the documentary does not seek to solve the case of who murdered the sisters, it shows that when they went missing their father was about to testify in a case against an alleged drug lord for whom he worked.

The father decided not to testify against the alleged drug lord, who the documentary showed as having close relationships with local police.

The film has won more than a dozen awards at film festivals around the world, after debuting at New York's famous Tribeca in 2011.

Hitting Philippines screens last year, it has become a must-see cautionary tale on the nation's justice system, with more than 100 law schools around the country having signed up to screen it for their students.

It also inspired the creation in December of the Innocence Project, a network of law schools and students who offer free legal help to convicts using DNA technology and investigative work to overturn wrongful convictions.

“The movie highlighted the defects and imperfections of the justice system,” project spokesman and law professor at the University of the Philippines, Jose Manguera Jose, told AFP. “There are so many wrongful convictions.”

The Philippines justice system has long been regarded as corrupt, with low-paid judges vulnerable to bribes and intimidation.

The current president, Benigno Aquino, has made fighting corruption throughout all part of society the top priority of his six-year term.

Justice Secretary Leila de Lima was non-committal when asked whether she thought Larranaga was innocent. “It is difficult to ascertain at this point whether there was a miscarriage of justice,” she said.

National police spokesman Generoso Cerbo declined to comment on the alleged corruption in the police force that was raised in the documentary.

Meanwhile Larranaga, now aged 35, remains behind bars in Spain.

Syjuco said that Spanish justice authorities, after seeing the film, no longer require him to admit his guilt in exchange for early release. He has also been permitted some trips outside of jail for therapy, including one to a film festival to watch the documentary.

However he remains ensnared in legal complexities and his final freedom remains far from certain.