The European Court of Human Rights (ECHR) ruled Friday that Belgium had committed a human rights violation by extraditing a convicted Tunisian terrorist to the US in October 2013.

Nizar Trabelsi, a 45-year-old former professional soccer player, was arrested in Belgium in the days following the attacks of September 11, 2001. Trabelsi was found in possession of weapons, fake passports, chemical formulas to make explosives, and detailed plans of potential targets, including the US embassy in Paris.

In 2003, a Belgian court found him guilty of planning a terror attack against the Kleine-Brogel military airbase in Belgium, which is allegedly used by the US to store nuclear missiles. Trabelsi admitted the charges and was sentenced to 10 years in jail.

In 2008, the US requested Trabelsi's extradition, two years after a district court in Washington, DC indicted him for conspiring with al Qaeda to carry out attacks against US nationals in Europe. According to the indictment, Trabelsi met with Osama bin Laden during a trip to Afghanistan in 2001.

Belgium agreed to hand Trabelsi over to Washington, on condition that he would be tried by a civil court — not a military tribunal — and that he would not receive the death penalty if found guilty. Belgian authorities also asked the US to guarantee that, in the case of a life sentence, Trabelsi would be able to apply for commutation, or a sentence reduction.

In 2011, the Belgian minister of justice granted the US its extradition order.

Trabelsi filed an appeal with the EHCR, saying that an extradition to the US could lead to a life sentence without parole, which would constitute a violation of his human rights. Life without parole, he argued, amounted to a breach article 3 of the ECHR, which stipulates that, "No one shall be subjected to torture or to inhuman or degrading treatment or punishment."

In 2011, the ECHR granted Trabelsi's request for "an interim measure" to block his extradition — a measure, which the Belgian justice system fought to have lifted.

In October 2013, Trabelsi was informed he was being transferred from Bruges Prison to Ittre Prison. Instead, he was driven to Melsbroek military airport, where he was met by FBI agents. He was extradited to the US, where he is currently jailed in Virginia.

In 2014, the ECHR found that, by exposing Trabelsi to the risk of an irreducible life sentence, Belgium had in fact violated his human rights. The court awarded Trabelsi damages of 60,000 euros in "non-pecuniary damage" and an additional sum of 30,000 euros to cover "costs and expenses."

Nizar Trabelsi in 1992. Photo via HORSTMUELLER/AP

Speaking to VICE News on Friday, Trabelsi's lawyer Marc Nève explained that the ruling in favor of his client could set a precedent for future US extradition requests, particularly with the UK, with whom the US has a controversially flexible extradition treaty.

Nève referenced a landmark ruling from 2013, in which the ECHR ruled in favor of three convicted British murderers, decreeing that jailing the men for life without parole was in breach of article 3 of the human rights convention, and that provision should be made for a review of sentences, no matter how serious the crime.

Paris attorney Florence Rouas-Elbazis explained to VICE News that when it comes to criminal cases, the European Union's community law supplants a country's domestic law.

While attorneys often rely on ECHR rulings to argue their cases in domestic courts, said Rouas-Elbazis, the case of Trabelsi stands apart. "[His case] is a bit unusual," she told VICE News, "because in cases involving terror suspects, there are always exceptional measures."

Nève said he intends to launch further legal proceedings against Belgium, to ensure the government would cease all legal collaboration with the US.

"We believe that, by pursuing a collaboration with the US," said Nève, "[the government] is continuing to violate the convention."