|Saif al-Islam has played a large role in Libyan politics while never holding an official position within the state [AFP]
Described last year by the New York Times as "the Western-friendly face of Libya and symbol of its hopes for reform and openness," Saif al-Islam Gaddafi, 39, is a fluent English speaker with a PhD from the London School of Economics.
The second of Libyan leader Muammar Gaddafi's seven sons, Saif al-Islam, whose name means sword of Islam, was given the task of defending his father's government after the start of the uprising against the elder Gaddafi's four-decade rule.
Widely seen as belonging to a camp that aimed to open Libya's economy, Saif al-Islam helped lead talks with Western governments that in the past 10 years saw Libya renounce nuclear weapons and end decades of isolation as a foe of the West, paving the way for large-scale investment in its oil sector.
Accused of money laundering by The Daily Telegraph in two articles published in 1995 (one of which focused on the alleged operation flooding "the Iranian economy with fake Iranian currency"), Saif al-Islam sued the UK newspaper for libel, prompting the Telegraph to issue an apology in 2002 for the "falsity of the allegations" levelled against him.
Saif al-Islam has clashed publicly with the ruling elite over proposals for reforms. Some analysts believe his conservative opponents have the backing of his brothers Mutassim, a national security adviser, and Khamis, a senior military leader. In December, he took the unusual step of denying a family feud with his brothers.
In 2008, the Associated Press news agency reported that Saif al-Islam announced that he was leaving politics, and that he had given, "no explanation for his decision", only dismissing reports of a rift between himself and his father.
He made his announcement via a televised statement, in which he also called for political reforms.
"I have decided not to intervene in state affairs," he said in the speech, broadcast on state television. "In the past, I used to intervene (in politics) due to the absence of institutions."
He said he would not succeed his father as the country's leader, adding that the reigns of power were "not a farm to inherit".
His turf war with conservatives escalated later, with many Libya-watchers seeing signs of his influence being held in check. Twenty journalists working for al-Ghad, a media group to which he was linked, were briefly arrested. The head of the group stepped down and its flagship newspaper stopped printing.
Much of his influence was wielded through his position as the head of a charity. Late last year the charity said it was withdrawing from politics and his post of chairman was being made into an honorary role.
Reformist image disappears
Saif al-Islam's reformist image vanished when the uprising against his father was launched from the eastern city of Benghazi in February, often going on television or giving press conferences to warn that opposition forces would be crushed.
As National Transitional Council (NTC) forces closed in on Tripoli late August, he went underground - only to reappear in the capital on August 23, just two days after reports that he had been captured by the fighters.
"We have a long breath," Saif said in his last public speech broadcast on television on August 21, 2011. "We are in our land and in our country. We will resist for six months, one year, two years ... and we will win."
"We will not submit, we will not abandon the fight," he said. "This is not the decision of Saif al-Islam or Gaddafi but the decision of the Libyan people."
But, he had not been heard from since, until a senior official of the ruling NTC announced that Saif had been arrested in the south of Libya.
Saif al-Islam has been in a secret prison in the custody of the Zintan fighters who captured him late last year during the country's bloody struggle to overthrow his father's regime.
The dapper 39-year-old is wanted by the International Criminal Court (ICC), which had earlier said it was negotiating his possible surrender.
ICC judges in June 2011 issued arrest warrants for Saif and his father as well as against intelligence chief Abdullah al-Senussi, for crimes against humanity allegedly committed since Gaddafi ordered his forces to wipe out the revolt.
All three were charged over their roles in the murder and persecution of civilians, particularly in Tripoli, Benghazi and Misrata, ICC prosecutor Luis Moreno-Ocampo said when the charges were announced.
Currently the NTC-lead Libya and the ICC are in negotiations as to where he will be tried with the country's justice minister most recently ruling out a trial by the ICC.
Saif al-Islam faces the death penalty if found guilty by a Libyan court and a prison term if convicted by the ICC.