ISLAMABAD: The family of American journalist Daniel Pearl will challenge an order by Supreme Court to release a British-born militant acquitted of masterminding his kidnapping and brutal murder in 2002.

The Supreme Court on Thursday upheld the acquittal of Ahmed Omar Saeed Sheikh and three other men last year, triggering outrage from the United States.

Pearl was the South Asia bureau chief for The Wall Street Journal when he was abducted and beheaded by jihadists in Karachi in January 2002 while researching a story about Islamist militants.

"The Pearl family intends to file a review petition against the illegal and unjust majority decision," parents Ruth and Judea Pearl said in a statement that was tweeted by the murdered journalist's friend and former Wall Street Journal colleague Asra Nomani.

They join both the federal government and Sindh government in launching a plea for the latest verdict to be reviewed.

Lawyers for Pearl's family have argued that Sheikh played a crucial role in organising the abduction and detention of the journalist before ordering his captors to kill him.

Defence lawyers, however, say he was a scapegoat and sentenced on insufficient evidence

"It is beyond belief that Ahmad Omar Sheikh -- who after 18 years of lies, had finally admitted in a handwritten letter to the court his role in the kidnapping for ransom of Daniel Pearl -- has been given a clean slate and let loose once again upon the world to continue his international terrorist activities," Pearl's family said in the statement.

The four men -- who have been detained under the emergency orders of Sindh government since their acquittal last year -- still have multiple court challenges linked to their case.

US President Joe Biden's administration was "outraged by the Supreme Court's decision", White House spokeswoman Jen Psaki told reporters last week.

The new US Secretary of State, Antony J. Blinken, on Friday spoke with foreign minister Shah Mahmood Qureshi, pressing his "concern about the potential release of these prisoners", a spokesman for the US Department of State said.