Rebel leaders in eastern Libya say they are in regular talks with a secret network of sympathisers inside the capital, Tripoli.
The rebels say they have about 100 underground contacts there, the BBC has learnt.
A member of the rebels' National Transitional Council (NTC) in Benghazi revealed to the BBC they were holding secret talks to prepare for the regime's fall.
The member says the talks are being held via Skype and satellite phones. He says he believes direct communications through Skype and satellite phones are secure "because no-one has been arrested yet.
The BBC reports the rebels want to gauge the impact of pressure from Nato air strikes and shortages on morale in Tripoli.
They also want to involve the Tripoli underground opposition in their general strategy for ousting Libyan leader Colonel Muammar Gaddafi.
