The parents of slain US journalist Daniel Pearl have petitioned to the Pakistani Supreme Court seeking to overturn a ruling that freed four men who had been convicted in 2002 of involvement in his killing.

Daniel Pearl execution
Slain Wall Street Journal reporter Daniel Pearl execution, who was abducted and beheaded in Pakistan in 2002.Twitter

Taking to Twitter, Pearl's father Judea said in an emotional video message: "We're standing up for justice, not only for our son, but for all our dear friends in Pakistan so they can live in a society free of violence and terrorism."

Their lawyer Faisal Siddiqi told Reuters he had filed the petition on their behalf. A court official said it had yet to be admitted for further proceedings.

"A bare perusal of the entire record would reveal that there was a plethora of incriminating evidence, both forensic as well as oral, which proved that murder was committed and that all the accused persons aided and abetted the murder," the appeal petition said.

Acquittal of Pearl's murder suspects

38-year-old Pearl was kidnapped and beheaded in January 2002 while investigating Islamist militants in Karachi, capital of the southern Sindh province.

Earlier this year, a court in Karachi overturned the death sentence of Islamist militant Ahmed Omar Saeed Sheikh, a Briton of Pakistani origin who was sentenced to death in 2002 for masterminding Pearl's murder, and acquitted three others for lack of evidence.

Pakistani authorities, however, ordered the four to be kept in detention for three months.

The ruling was widely condemned.

The United States denounced the high court ruling, with the top US diplomat for South Asia saying it was "an affront to victims of terrorism everywhere".