A Kuwaiti national suspected of belonging to the Islamic State in Iraq and Syria (ISIS) will appear before the Public Prosecution on Tuesday.
According to Al Qabas newspaper, Hussain Al Dhafiri was extradited from the Philippines to his home country aboard a military plane to face charges.
The Public Prosecution is expected to remand him in custody pending the investigation.
Public Prosecutor Dherar Al Asoussi ordered four relatives of Al Dhafiri to be held in custody for 21 days in the central prison on suspicion of being ISIS members.
The Philippine security forces arrested the suspect and his five-month pregnant Syrian wife Rahaf Zina for suspected links to Islamic State three months after they arrived.
The couple had been living and working in Manila since January before they were arrested on March 25 in an upscale commercial district.