A court Friday ordered the imprisonment of a Frenchman who was released this month from the U.S. military prison at Guantanamo Bay, Cuba, his lawyer said. Ridouane Khalid, 36, had been free but under judicial watch in France after returning home from Guantanamo on March 7. The court also ruled that another former Guantanamo detainee, 33-year-old Khaled ben Mustafa, must remain behind bars. In a hearing Tuesday, the prosecution argued that both men pose a threat to public order and should be jailed while their cases are investigated by French authorities. Khalid and ben Mustafa, among seven French nationals who were detained at Guantanamo, were captured in December 2001 as they tried to enter cross the Afghan-Pakistani border. Both are under investigation - one step short of being formally charged - for "criminal association with a terrorist enterprise." Four of the French detainees returned to France in July and remain in custody on similar charges. The United States handed over Khalid, ben Mustafa and a third man, Mustaq Ali Patel, this month.