Saudi security authorities arrested Sayyed Zabihuddin Ansari, an Indian Muslim and a leading figure in Pakistan's Lashkar-e-Toiba Islamist organization, in June. He was deported to India to face charges linked to the Nov. 26, 2008, attack on Mumbai.
During that 72-hour rampage by 10 gunmen infiltrated from Pakistan, 166 people, including six Americans, were killed.
It was the first time Riyadh has extradited an Indian terror suspect, indicating a stronger commitment by the kingdom, which is custodian of Islam's holiest shrines, to the global fight against terrorism.
The Jamestown Foundation, a Washington think tank that monitors global terrorism, observed that "at a time when questions are being raised about Saudi Arabia's tacit support for the global Salafist movement, recent developments have displayed the kingdom's new-found seriousness in fighting terrorism, especially that emanating from South Asia."
Jamestown says that what's occurring is a "new wave of counter-terrorism cooperation from Saudi Arabia" in which "India is attempting to target other Indian terrorist fugitives currently holed up in Saudi Arabia and the (Persian) Gulf region."
Saudi Arabia and India signed an extradition treaty February 2010. Western security officials insist it's not clear whether this signifies a new policy by Riyadh, which could aggravate the kingdom's long-close relations with Muslim-dominated Pakistan, or is a one-shot affair.
Jamestown said Ansari's arrest and deportation "took months of diplomatic negotiations, with the United States playing an active role" to persuade Saudi authorities to overcome their long-standing pro-Pakistan policies."
Even so, Jamestown stresses that "Saudi authorities have conveyed to their Indian counterparts that while they may be prepared to extradite Indian nationals to India, they wouldn't necessarily act against Pakistan nationals wanted for terrorist acts in India."
The Saudi position will become clearer if Riyadh extradites another Indian suspected of being an LeT operative, Fasih Mehmood, whom they reportedly have in custody.
Diplomatic sources say Mehmood was arrested May 13 in Jubail in eastern Saudi Arabia in response to an Interpol alert.
New Delhi accuses Mehmood of involvement in the April 17, 2010, bombing of a Bangalore cricket stadium and the Sept. 19, 2010, attack on a New Delhi mosque.
Mehmood's whereabouts aren't known but India is pressing Riyadh to extradite him.
Jamestown cites reports that "some regulatory bottlenecks" have delayed his extradition.
However, the focus is primarily on Ansari, aka Abu Jundal and Abu Hamza, who is believed to be the highest ranking Indian in the LeT, which is closely linked to al-Qaida.
LeT for years concentrated on fighting India in Kashmir, which is divided between India and Pakistan. But recently, LeT has become a serious player in international terrorism. It's widely believed to be largely controlled by Pakistan's principal intelligence agency, the Inter-Services Intelligence directorate.
Security sources say Ansari was sent to Saudi Arabia by LeT to "mobilize resources for the next big attack against India."
Putting him in the hands of India's intelligence services could harm Saudi relations with Pakistan because it will harden New Delhi's case that the ISI is deeply involved in terrorist attacks by Islamic extremists against India.
This could heighten the animosity between Islamabad and Washington that stems largely from the unilateral U.S. use of missile-firing unmanned aerial vehicles against al-Qaida, LeT and other jihadist organizations in the badlands of northwestern Pakistan in which large numbers of civilians have been slain.
Pakistan refuses to hand over to India the masterminds of the Mumbai massacre. But Ansari is the third alleged LeT operative to provide evidence of Pakistani complicity in the carnage.
The first was Mohammed Ajmal Kasab, the only one of the 10 attackers who was captured alive. He now sits in a Mumbai prison cell facing a death sentence.
During his trial, he said a man known as "Abu Jundal" trained the death squad and directed them from a "control room" in the Pakistani city of Karachi during the attack.
The other is David Headley, a Pakistan-American LeT operative in U.S. custody. He carried out the reconnaissance of Mumbai before the attack.