ISLAMABAD, Pakistan (AP) – The top al-Qaeda operative who masterminded the Sept. 11 attacks either killed or participated in the murder of American journalist Daniel Pearl, Pakistan’s president has alleged for the first time.

President Gen. Pervez Musharraf’s claims could now be used to try clear one of Pearl’s four convicted killers, who is appealing his death sentence, the prisoner’s lawyer said on Wednesday.

In his memoirs released this week, Musharraf accused Khalid Sheikh Mohammed, who is in U.S. custody in Guantanamo Bay, of taking part in Pearl’s killing in Pakistan’s largest city, Karachi, following his kidnapping on Jan. 23, 2002.

“The man who may have actually killed Pearl or at least participated in his butchery, we eventually discovered, was none other than Khalid Sheikh Mohammed, al-Qaeda’s No. 3,” Musharraf wrote “In The Line of Fire,” released Monday.

Mohammed has never been officially linked to Pearl’s murder, neither during police investigations nor the trial that resulted in four Islamic militants being convicted and sentenced to death for the killing.

But some U.S. officials and Pearl’s newspaper, the Wall Street Journal, suggested after Pearl’s death that Mohammed had killed him. Pakistan had denied the claims at the time.

On Wednesday, Rai Bashir, lawyer for British-born Pakistani Ahmed Omar Saeed Sheikh, said he will petition the Sindh High Court in Karachi within 10 days to let him introduce Musharraf’s book as evidence in his client’s appeal case, which began in January 2003.

Sheikh and three other Islamic militants were convicted in July 2002 for killing Pearl. They have all since appealed the ruling.