Seif al-Islam, the son of slain Libyan dictator Moamer Kadhafi who registered to run in December's presidential poll, is wanted for war crimes by the International Criminal Court.
For years mystery surrounded the whereabouts of the man long considered the likely successor to Kadhafi who was killed in a popular uprising in 2011.
Seif al-Islam's first public appearance in years came in the form of an interview with The New York Times published in July, in which he did not rule out a political comeback.
"It is time for a return to the past. The country -- it's on its knees... There's no money, no security. There's no life here," Seif al-Islam told the newspaper.
On Sunday, Libya's electoral commission said that Seif al-Islam registered to run for the oil-rich North African country's presidential election which is slated to take place on December 24.
"Seif al-Islam Kadhafi submitted... his candidacy for the presidential election to the High National Electoral Commission office in the (southern) city of Sebha," a statement said.
He was seen registering his candidacy dressed in traditional robes and headdress.
Born in 1972, Seif al-Islam, whose name means "sword of Islam", is the second of Kadhafi's eight children, the eldest son of his second wife Safiya.
He received a doctorate from the London School of Economics but held no official post during his father's more than 40 years of rule.
- Dapper face of Kadhafi regime -
But Seif al-Islam long served as the face of Kadhafi's regime in the West, appearing in suit and tie, and speaking fluent English.
He shot to prominence in 2000 when the Kadhafi Foundation that he headed negotiated the release of Western hostages held by Muslim rebels in the Philippines.
Seven years later he served as a mediator over the release from Libya of Bulgarian nurses jailed over a hospital AIDS outbreak.
He also negotiated compensation agreements for the families of those killed in the 1988 Lockerbie plane bombing and a blast that downed French UTA Flight 772 over Niger in 1989, both of which were blamed on Libya.
He was also the architect of reform, anxious to normalise ties with the West.
But the Arab uprisings which swept the region a decade ago instead left him as the last major holdout of a regime brought to its knees and eliminated by a NATO-backed revolt.
Three of Kadhafi's sons were killed in the uprising that ended his regime.
And Seif al-Islam's reformist image vanished during the revolt, when he often appeared on television or gave news conferences to warn that opposition forces would be crushed.
- Sentenced to death for war crimes -
As National Transitional Council (NTC) forces closed in on Tripoli in late August 2011, he went underground -- only to reappear in the capital on August 23, just two days after reports he had been captured by the rebels.
He was not heard from afterwards, until his capture by a Libyan militia in November 2011, days after his father was killed.
Four years later, a Tripoli court sentenced him in absentia to death for crimes committed during the revolt.
A rival administration in the east later pardoned Seif al-Islam but the decision was never confirmed by authorities in Tripoli.
The ICC has repeatedly asked for him to be handed over for trial for crimes against humanity, specifically "murder and persecution" allegedly committed using state forces across Libya in February 2011.
Until the Times interview, Seif al-Islam had not been seen or heard from since June 2014, when he appeared via video link from Zintan in the west of the country during his trial by the Tripoli court.
In the interview, the 49-year-old said that he was a free man organising a political return.
Any possible return by Seif al-Islam to Libyan politics would face hurdles, including his conviction by the Tripoli court and the ICC arrest warrant.
But Seif al-Islam seems undeterred, according to the Times.
The son of the slain dictator said "he was confident that these legal issues could be negotiated away if a majority of the Libyan people choose him as their leader".
The paper quoted him as saying: "I've been away from the Libyan people for 10 years. You need to come back slowly, slowly. Like a striptease. You need to play with their minds a little."