Moammar Gadhafi's son Saif al-Islam Gadhafi is thought to hiding in the Sahara Desert, where he could potentially remain undetected for months.

Saif al-Islam has not been seen in public since the fall of Tripoli in August. The last news of the one-time heir apparent was that mercenary Tuareg tribesmen were escorting him through the desert sands last week.

While some reports suggest that Saif al-Islam has escaped to either Niger or Mali, officials in both countries deny the claims.

My latest information is that they are not in Mali and they are not in Niger yet either, Malian legislator Ibrahim Ag Mohamed Assaleh told The Associated Press.

Saif al-Islam has been wanted by the International Criminal Court (ICC) for war crimes and crimes against humanity since June.

The Hague accused Saif al-Islam and his father for shooting unarmed civilians during protests in February.

The court is also gathering evidence concerning mass rapes, and investigating reports that Gadhafi ordered his security forces to use rape as military tactic.

ICC chief prosecutor Luis Moreno-Ocampo is trying to convince Saif al-Islam to surrender.

Someone close to Saif ... was asking a few questions about the possible surrender of Saif to the ICC, including questions about what happened if he is convicted, what happens if he is acquitted, where he is going, so we clarified this issue -- but we have nothing to negotiate, Ocampo told Al Arabiya.

Ocampo reportedly told the contact that the United Nations would provide Saif al-Islam with safe passage and a plane to The Hague. Ocampo added that there's a possibility the former Libyan heir could live freely in any country that would accept him.

Ocampo again made it clear that Saif al-Islam would be prosecuted for this alleged crimes.

If Saif surrenders, he has to go to The Hague, then immediately he will go before the judges, who will inform him of his rights, and then his lawyer will have to start to receive our evidence, and then we go to the confidential charges, he explained.

Moammar Gadhafi's former head of military intelligence Abdullah Senussi is also on the lam. It was originally thought that he was travelling with Saif al-Islam, but Al Arabiya says that Senussi is now in Mali, having fled through Niger.

Pre-empting any border-crossing attempt, Niger has stated that if Saif al-Islam enters the country he will turned over to the ICC. During the revolution, a number of high-ranking Gadhafi ex-generals and cabinet members fled safely to Niger, and Saif al-Islam's brother Saadi escaped into Niger with the help of Canadian bodyguards.

Niger has told the National Transitional Council that they will not return Saadi any time, but the new Libyan government can come to the capital city of Niamey and question him.

If it is to question Saadi, the National Transitional Council (NTC), which we have recognized, can freely come to Niger, under the existing accord, Niger's justice minister, Marou Amadou, told Reuters.

However, I reaffirm that at this stage...there is no possibility of extraditing Saadi, because ultimately what needs to be applied is international conventions, he said.

During his rule, Moammar Gadhafi was a popular figure in Niger. Many ethnic Tuaregs in Niger and in Mali fought in Gadhafi's army as mercenaries, and even more Nigeriens led prosperous lives working in Libya.

Since fighting began in Libya in February, more than 200,000 Nigeriens fled Libya, where they were earning unheard-of sums, by local standards, as tailors, security guards, cooks and drivers, according to the New York Times, damaging Niger's national economy by $80 million.