The recent death of Rubin "Hurricane" Carter, the American middleweight boxer who spent almost 20 years in jail for three murders he did not commit, has turned the spotlight on the issue of wrongful convictions.

Carter’s incarceration from 1966 to 1985 caused an international outcry, turning him into a symbol of racial injustice and inspiring Bob Dylan’s famous protest song “Hurricane.”

There are hundreds, if not thousands, of people languishing in jails around the world, serving sentences for crimes they didn’t commit.

A recent statistical study published in the journal Proceedings of the National Academy of Sciences showed about one in 25 people jailed under a death sentence in the United States were likely innocent.

But there is hope. Thanks to the efforts of an international organization called The Innocence Network, more and more innocent people are being freed.

The Innocence Network was founded in 2005 and now has 58 members scattered around the world, including the United States, Canada, Australia, New Zealand, Britain, Ireland, South Africa, France, Italy and the Netherlands.

Members are law schools, journalism departments and public defenders providing free legal and investigative services to inmates seeking to prove their innocence.

One of the founding members — and perhaps the most famous — is the Innocence Project in New York, which is affiliated with the Benjamin N. Cardozo School of Law at Yeshiva University.

Set up in 1992, the Innocence Project was the first such organization to use DNA technology to overturn wrongful convictions. (DNA began to be used as evidence in criminal cases in the late 1980s.)

At last count, it has helped free 172 people.

In 2013, members of the Innocence Network helped exonerate 31 people around the world — the highest number since the organization began reporting its results five years ago. They had served a cumulative 451 years in prison.

Demand for Innocence Network services is huge.

The Innocence Project alone receives more than 3,000 requests for help every year and at any given time it is assessing 6,000 to 8,000 potential cases.

Here are some of their success stories:

Steven Truscott: 10 years in jail

Photo courtesy of The Association in Defence of the Wrongly Convicted

In June of 1959 Steven Truscott’s life was upended. Truscott, then aged 14, was charged with murdering his classmate, Lynne Harper, whose body was found near Clinton in Ontario, Canada, two days after Truscott was seen giving her a ride on his bicycle. She had been sexually assaulted and strangled. Truscott was convicted and sentenced to life imprisonment. After 10 years, he was freed on parole and he spent the next four decades trying to clear his name. The Association in Defence of the Wrongly Convicted took up his case in 1997 and uncovered fresh evidence, including two unofficial autopsy reports that gave different times of death to the one given at Truscott’s trial and that proved he could not have killed Harper. Truscott’s conviction was declared a miscarriage of justice and was quashed in 2007. He later received $C6.5 million in compensation.

Tammy Marquardt: 14 years in jail

Photo courtesy of The Association in Defence of the Wrongly Convicted

In 1995 Tammy Marquardt, then 23, was given a life sentence for the murder of her two-year-old son, Kenneth, who suffered asthma and epilepsy. Her conviction largely rested on the testimony of Charles Smith, a former pathologist at the Hospital for Sick Children in Toronto who was considered at the time a leading expert in suspicious pediatric deaths. Smith performed the autopsy on Kenneth and concluded Marquardt had strangled or smothered her son to death. While Marquardt languished in prison for 14 years, the AIDWYC pushed for an investigation into Smith’s work. A 2008 public inquiry found Smith had made fundamental errors in 20 child autopsies, the majority of which resulted in criminal convictions. Several convictions, including Marquardt’s, were later overturned. Smith was later stripped of his medical license.

Nozai Thomas and Andy Melaan: 4.5 years and eight years in jail, respectively

Nozai Thomas, far left, and Andy Melaan, third from left, pose for a photo with their Knoops' defense team. Belkis Osepa/Caribisch Netwerk

In 2006, a court sentenced Nozai Thomas and Andy Melaan to eight years and 24 years, respectively, for the 2005 murders of two brothers on the Caribbean island of Bonaire, which is a special municipality of the Netherlands. The convictions were based on statements from a third suspect, who was later sentenced to 18 years, and the — retracted — confession of Thomas. After the Amsterdam-based Knoops’ Innocence Project got involved in the case in 2011, IT experts were able to prove that Thomas had been using his computer at home at the time of the killings, while cellphone records showed Melaan had been on the other side of the island. A new trial was ordered and in November 2013 the pair was exonerated. Both men were awarded a total of nearly $2 million in compensation for their ordeal.

George Allen, Jr: 30 years in jail

Photo courtesy of the Innocence Project

George Allen, Jr., walked out of Jefferson City Correctional in Missouri on Jan. 18, 2013 after serving 30 years in prison for a murder he did not commit. At 56, Allen had spent more than half of his life behind bars. In 1983, Allen was sentenced to 95 years in jail for the murder of Mary Bell, a court reporter. The conviction, according to the Innocence Project, which began a DNA testing investigation in 2003, was based on a “false confession, police ‘tunnel vision’ and blood type evidence that was said to include Allen but actually eliminated him as a possible contributor.”

Bennie Starks: 20 years in jail

Photo courtesy of the Innocence Project

Eyewitness misidentification and incorrect bite mark analysis, among other things, resulted in Bennie Starks spending 20 years of his life in the Illinois River Correctional Center in Canton for a sexual assault he didn’t commit, according to the Innocence Project. Starks was convicted in 1986 on charges of rape and battery of a 69-year-old Hispanic woman. He was freed in 2006 on a bond after DNA testing of a vaginal swab from the victim’s rape kit excluded Starks, but it wasn’t until January 2013 that he was officially cleared of all charges. He was 53.