Mustafa Abdel-Jalil, head of the National Transitional Council, told the Associated Press on Monday that rebels detained al-Saadi Gaddafi on Sunday night along with his brother Seif al-Islam.
Gadhafi's sons and a daughter have all played roles in their father's regime, some in diplomatic or business roles. Al-Saadi and his brothers Mutassim and Khamis all headed military brigades.
The International Criminal Court has confirmed the capture of Seif al-Islam, who along with his father faces charges of crimes against humanity. Another son, Mohammed, was under house arrest.
U.S. officials were in frequent contact Monday with Libyan rebels as they claimed control of most of Tripoli. A top American diplomat said the whereabouts Moammar Gaddafi were still unknown, but the Pentagon said officials believe he's still in the country.
France calls for Libya meeting
Meanwhile the French government called for an extraordinary meeting to set up aid and support for the Libyan leadership that appears likely to take over from Gaddafi's government.
The call came after French President Nicolas Sarkozy spoke with Mahmud Jibril, head of Libya's National Transitional Council (NTC), and invited him to France on Wednesday.
Foreign Affairs Minister Alain Juppé said at a news conference that the French government wants to hold a meeting of the contact group—an informal gathering of countries supporting the transitional council—"at the highest level" in Paris as soon as next week to discuss the situation in Libya and the need to build a democracy there.
Arab countries back Libyan rebels
Arab countries declared "full solidarity" with Libya's NTC as rebels closed in on Gaddafi's Tripoli compound in their final drive to oust him.
Arab League chief Nabil al-Arabi expressed in a statement his "full solidarity with the ongoing efforts" by the NTC, and "wished success for the council in leading a new era and preserving Libya's regional integrity and its sovereignty and independence."
Egypt recognizes Libya’s rebel government
Egypt, Libya's eastern neighbor, recognized the council as the legitimate government after holding back so far on supporting the rebels, who started their uprising days after an Egyptian revolt ended president Hosni Mubarak's three decade rule.
Turkish FM to fly to Libya
Turkish Foreign Minister Ahmet Davutoglu said he would fly to the Libyan rebel capital of Benghazi on Tuesday.
Speaking in the Ethiopian capital, Addis Ababa, Davutoglu told reporters: "From here I will travel to Benghazi as foreign minister of Turkey but, at the same time, as chairman of the international Libya contact group."
"There is a beginning of a new era in Libya for a future, democratic, united Libya. What we always defended as Turkey was a new Libya based on the aspirations of the people of Libya without being divided and without there being a chaotic situation," he said at the African Union's headquarters where an emergency meeting on Libya had just begun.
Switzerland calls for restraint in Libya
Switzerland called on all sides to show restraint and to do their utmost to protect the civilian population in the Libyan capital, Tripoli.
In a statement on Monday, the foreign ministry called on the regime of Moammar Gaddafi to “leave power immediately, to prevent further suffering by the civilian population”.
In addition, Swiss Foreign Minister Micheline Calmy-Rey told an ambassadors’ conference in Lucerne that she was happy about what appeared to be the approaching end of the Gaddafi regime and welcomed greater freedom and democracy for the Libyan people.
International court to discuss transfer of Libya suspects
The International Criminal Court's prosecutor on Monday said he had contacted Libyan rebels but needed more talks to determine how to transfer arrested suspects such as Saif al-Islam Gaddafi to The Hague.
Prosecutor Luis Moreno-Ocampo said he held talks with the rebels' council on Monday about its efforts to stabilize the situation in Tripoli and to establish security, and that he was committed to support these efforts.
"Further conversations will define the precise way to move forward, including the possibility to apprehend and surrender to the court the three individuals alleged to have committed crimes," Moreno-Ocampo said in a statement.
South Africa denies sending plane for Gaddafi
South Africa says it has not sent planes to Libya to help Gaddafi flee his country.
In a statement Monday, the government said it wished to dispel rumors that South African aircraft will fly Colonel Gaddafi and his family to an undisclosed location.
Foreign Minister Maite Nkoana-Mashabane told reporters that the Libyan leader has not asked for asylum in South Africa, adding that she is sure he will not do so.
Separately, officials in Zimbabwe are denying that Gaddafi could be headed to their country.
The ministry of foreign affairs in Harare said Monday there is no substance to reports that Gaddafi might find refuge in Zimbabwe.
And, a spokesman for the MDC, one of two major parties in Zimbabwe's unity government, tells VOA that the party would block any effort to extend asylum to the Libyan leader.
A correspondent for al-Jazeera television said earlier Monday that Zimbabwe was a possible destination for Gaddafi. In 1991, Zimbabwe granted asylum to former Ethiopian dictator Mengistu Haile Mariam, who still lives in the country.
Meanwhile, in Addis Ababa Monday, Libya's ambassador to the African Union declared an end to Gaddafi's rule. He also removed the Gaddafi-era flag from Tripoli's embassy in Addis, replacing it with the pre-Gaddafi flag used by rebels.
The AU Peace and Security Council met Monday to discuss the latest developments in Tripoli. African heads of state are to discuss Libya in meetings later this week.
South Africa said Monday it backs an AU roadmap that calls for a transitional Libyan government, the drafting of a new constitution, and Libya's first-ever democratic elections.
(Source: Agencies)