Pakistan's supreme court ordered the immediate release of a British-born militant acquitted of the 2002 murder of American journalist Daniel Pearl, a decision the reporter's family called a travesty of justice.
A three-judge bench on Thursday rejected petitions to overturn the acquittal of Ahmed Omar Saeed Sheikh and three associates and declared they should instead be freed, his lawyer said.
"According to the Supreme Court, these people should not have been imprisoned for one day," said Sheikh's lawyer, Mahmood Sheikh.
The decision is likely to cause anger in Washington, which has long accused Pakistan of being soft on terrorism. Late last year, the US suggested it would pursue Sheikh if Pakistan freed him.
"Today's decision is a complete travesty of justice and the release of these killers puts in danger journalists everywhere and the people of Pakistan," the Pearl family said.
Asra Nomani, a friend and former colleague of Pearl who was working with his family to appeal against the acquittal, said: "I'm in shock. What a betrayal. How could you let this happen on your watch Imran Khan? First Danny Pearl is murdered on your soil. And now justice is slain."
Sheikh was sentence to death in 2002 for masterminding the kidnap and murder of the Wall Street Journal bureau chief.
Pearl was kidnapped while investigating links between Pakistani militants and Richard Reid, known as the Shoe Bomber after trying to blow up a flight from Paris to Miami with explosives hidden in his shoes.
Sheikh's original trial heard he had been in contact with Pearl and promised to introduce the reporter to a religious leader in Karachi.
Pearl was instead kidnapped outside a restaurant and held in a compound on the outskirts of the city.
He was beheaded and a video of his murder shared on the internet. The horrific crime came to set a template for extremist killings.
Yet in April the Sindh High Court ruled there had been discrepancies in the original prosecution and the charges were not proven.
Pakistan had been under intense US pressure to find the culprits and concocted evidence against Sheikh and three others to make them scapegoats, his lawyers said.
"The way I look at it, their lives, the prime of their lives, has been wasted in jail without them having committed any offence whatsoever," Sheikh's lawyer said after the 2-1 Supreme Court ruling.
"The court said he should be released forthwith if he's not required in any other case."
A journalistic investigation led by Ms Nomani in 2011 concluded that Sheikh had not committed the final execution and the actual killer was Khalid Sheikh Mohammed, a member of Al Qaeda and mastermind of 9/11.
Yet Sheikh still orchestrated the terrorism-motivated kidnap and much of the plot, and Ms Nomani and the family said he was responsible for Pearl's death.
Sheikh and the three other men convicted of involvement in the kidnapping have been held under emergency orders by the Sindh provincial government since their acquittal in April 2020.
It was not immediately clear whether the government would abide by the Supreme Court ruling and free the men straight away.
Last month, Jeffrey Rosen, US attorney general at the time, said the US "stands ready to take custody of Omar Sheikh to stand trial here" and described the acquittal as "an affront to terrorism victims everywhere".