Four men were wrongfully convicted of the murder of Wall Street Journal reporter Daniel Pearl nine years ago, while the actual killer is the suspected mastermind behind the 9/11 terror attacks, a new investigation alleges.

The revelations, which include the allegation that a dozen terrorists involved in the killing are still at large and operating, are based on a three-year investigation by the Pearl Project conducted by journalism students and faculty at Georgetown University and the International Consortium of Investigative Journalists.

Heading the probe was a Asra Nomani, Pearl’s colleague, from whose house in Karachi, Pakistan, the reporter left on the day of his 2002 disappearance supposedly for an interview with a high-level terrorist source.

The four men convicted in the slaying remain in jail, but the actual killer is Khalid Sheik Mohammed, the key figure in the 2001 attack on New York’s World Trade Center, according to the project analysis.

Mohammed told U.S. investigators at Guantanamo Bay that he slit Pearl’s throat and severed his head, the report said, with independent forensic evidence pointing in a similar direction.

However, Washington officials decided not to charge Mohammed, fearing it would complicate their case against him in the 9/11 prosecution, the report stated.

Judea and Ruth Pearl, the parents of Daniel Pearl, said they are still “trying to digest” the report and did not wish to go into details at this point.

Judea Pearl said, however, that the authors were “good and honest people who [conducted the project] with love.” Ruth Pearl added that the project investigators had phoned frequently and that she and her husband had provided valuable contacts.