(CBS/AP) -- Egyptian officials told CBS News Wednesday morning that Saif al-Adel, a senior al Qaeda operative who was close to Osama bin Laden as opperations chief for the terror group, had been arrested after arriving on a flight to his native Egypt, but the man in custody claims it is a case of mistaken identity, and U.S. officials seem to agree.
Officials with Egyptian airport security and the Egyptian Interior Ministry told CBS News' Alex Ortiz that al-Adel was taken into custody after arriving in Cairo on a flight from Dubai, but that he gave another name, Mohammed Ibrahim Makkawi, and claimed he was not the al Qaeda leader.
Speaking to reporters at the airport, the man claimed he was not Saif al-Adel and that he had had nothing to do with the terror group since 1989.
U.S. officials tell CBS News correspondent Bob Orr they do not believe the man detained in Cairo is Saif al-Adel, and it appears the detained man's claim of mistaken identity is likely valid.
The U.S. has listed the name Mohammed Ibrahim Makkawi as the real name of Saif al-Adel, a pseudonym that means "sword of justice." But an al Qaeda scholar tells CBS News there are two different Makkawis, so a case of mistaken identity is possible.
Doc. Omar Ashour, a visiting shcolar at the Brookings Institution, tells CBS News the person held in Cairo may be another Mohamed Ibrahim Mekkawi - also a former Egyptian army officer who was a member of al Qaeda until the early 1990s - who has since disavowed al Qaeda's methods and even spoken publically against the group.
Ashour could not confirm the identity of the man being held Wednesday in Cairo, as he had not seen any images of the suspect.
The security source at Cairo airport, contacted later by Ortiz, seemed to back down from his initial insistence that the man arrested was, in fact, al-Adel.
Al-Adel remains on the FBI's most wanted terrorists list for "Conspiracy to Kill United States Nationals, to Murder, to Destroy Buildings and Property of the United States, and to Destroy the National Defense Utilities of the United States".
A senior Western diplomat notes to CBS News' Farhan Bokhari that al-Adel's high profile would likely have made booking a commercial flight difficult. Ashour, the scholar, also said it was hard to believe that the real al-Adel would have been able to board a commercial flight.
As a senior member of al Qaeda's leadership, al-Adel will possess a wealth of information on the group's operations and potentially the movements of its other top figures.
Last year, a senior diplomat in Pakistan told Bokhari al-Adel was "a bit annoyed" when Ayman Al-Zawahiri was named the new leader of al Qaeda after bin Laden was killed in a U.S. Navy SEAL raid.
Al-Adel is believed to have taken temporary charge of the group after bin Laden's killing, but Zawahiri was officially appointed the new leader several weeks later.
Orr says U.S. officials believed al-Adel was likely in Pakistan following bin Laden's death, but had since traveled to Iran. At that time, the U.S. officials said al-Adel was not likely still involved in al Qaeda's operations, but they still viewed him as a key member of the group's inner circle.