MADRID, Spain (CNN) -- A Moroccan terror suspect held in Britain was extradited Friday to Spain, where he faces possible charges of conspiracy in the Sept. 11, 2001 attacks in the United States and membership in a terrorist group, a Spanish court source told CNN.
Flanked by Spanish police Farid Hilali arrives in Madrid on Friday to face terrorism charges.
The suspect, Farid Hilali, 39, was arrested in Britain in 2004 on a Spanish warrant but had been fighting extradition, eventually losing his legal battles to stay out of Spain, a Spanish National Police statement said Friday.
Hilali was due to appear later Friday in Madrid, the court source said, before Judge Baltasar Garzon, who named Hilali in a 2003 indictment of suspected members of a Spanish cell of al Qaeda.
Twenty-four of those suspects stood trial in Madrid in 2005, including three key defendants charged with conspiracy in the Sept. 11 attacks. But the court acquitted two of them on that charge, and convicted only one, Syrian-born Imad Eddin Barakat Yarkas, on the conspiracy charge.
Yarkas appealed to Spain's Supreme Court, which in 2006 threw out the conviction for conspiracy in the 9/11 attacks but upheld the lower court's conviction of Yarkas as leader of an al Qaeda terrorist cell in Spain. Yarkas is currently serving a 12-year sentence in Spain.
Hilali's alleged connection to the 9/11 conspiracy was through a series of phone calls with Yarkas, which authorities secretly monitored.
Some media reports have linked Hilali to a call to Yarkas from London shortly before the 9/11 attacks, in which the caller referred cryptically to entering "the field of aviation" and "cutting the bird's throat."
But the court source said it may now be difficult to press charges against Hilali for conspiracy in the 9/11 attacks, given that Spanish courts have acquitted at trial or on appeal three other suspected co-conspirators, including Yarkas.
But Hilali also faces a potential charge of membership in a terrorist group, which may be easier to uphold in court, the source said.
In the 2005 trial, the National Court convicted 18 of the 24 defendants for al Qaeda and terrorism links, acquitting six. But in 2006, the Supreme Court overturned the convictions of three men, leaving a total of just 15 defendants convicted of some terrorism charges in the case that started under Garzon's investigation. E-mail to a friend