An independent report prepared for the United Nations says UN-led sanctions against al-Qaeda are ineffective and have had limited impact.
The report, which is expected to be formally released on Monday, is expected to say that the current system of sanctions and travel bans have failed to keep pace with the changing nature of the terrorist threat.
The report recommends that efforts are improved to prevent the flow of money between groups and individuals suspected of terrorist links.
The reports says that the UN's own sanctions have had limited impact and identifies the small finance required to fund the attacks.
The Madrid bombings last March are estimated to have cost $10,000.
The report says that as al-Qaeda has become an increasingly disperse network with little central direction, stopping the flow of funds has become increasingly difficult.
