An Interior Ministry statement said Friday that Jabir Jubran al-Fayfi contacted Saudi authorities from Yemen to express his regret and readiness to surrender. Yemeni authorities arranged for his return.
Al-Fayfi was released from Guantanamo in 2006.
He rejoined al-Qaida in Yemen, where the terror network's local offshoot is attacking Western targets and Yemeni security forces and leaders. The offshoot also claimed responsibility for the failed attempt to bomb a Detroit-bound airliner in December.
The Saudi rehabilitation center says 11 of the 270 militants who finished the program rejoined al-Qaida.