Saif al-Islam Gadhafi, a fugitive son of the recently killed Libyan dictator Moammar Gadhafi, is near Libya's borders with Niger and Algeria and planning to flee the country using a forged passport, according to the National Transitional Council.

He's on the triangle of Niger and Algeria, an NTC official told Reuters by telephone. He's south of Ghat, the Ghat area. He was given a false Libyan passport from the area of Murzuq.

The official said Moammar Gadhafi's former intelligence chief Abdullah al-Senussi was involved in the escape plot.

In the south, they intercepted Thuraya (satellite telephone) communications, the official said. Abdullah Senussi has been on the border in that area to organize his exit and also a neighboring intelligence source tipped us off about that.

Saif al-Islam, a fluent English speaker who studied at the London School of Economics, is the only one of Gadhafi's sons still unaccounted for.

Two fled to Algeria, one is in Niger, two were killed earlier in the Libyan conflict and one, Mo'tassim, was killed after being captured with his father last week near the city of Sirte.

The International Criminal Court earlier this year issued an arrest warrant for Saif al-Islam, and another for al-Senussi.

The official said it would be difficult to track Saif al-Islam's movements and stop him crossing out of Libya.

The region is very, very difficult to monitor and encircle, the official said. It needs warplanes. Even NATO cannot monitor this area. It needs a large force of our brigades to intercept and to be able to monitor and hunt him down. It is very, very difficult. All we have there is some small-scale patrols of our fighters. The region is a desert region and it has many exits. It is also a smuggling route. It has many, many exit routes.