A leaked study by the United Nations says that efforts to cut off funding to the al-Qaeda network are failing.
The report says countries are not co-operating
The report blames inadequate co-operation, legislative loopholes and a lack of political determination, the UK's Financial Times newspaper says.
The study says two suspected al-Qaeda fundraisers are still active in Italy and Switzerland, the newspaper reports.
It also says the international arms embargo against al-Qaeda is not working and needs to be overhauled.
The report says that despite a system of financial checks designed to impede the activities of terrorists, many countries are not adequately sharing information, the newspaper reports.
Since the 11 September 2001 attacks on the United States, countries are required to submit lists of individuals and organisations linked to terrorist groups to a UN committee.
But, according to the study, many countries have failed to act and have been reluctant to seize properties and businesses, the Financial Times reports.
The newspaper cites the report as saying the arms ban on al-Qaeda is "totally ineffective" in some aspects and needs to be "completely revamped".
It also reported as saying charities suspected of being linked to al-Qaeda remain active and difficult to control because of their involvement in humanitarian work.
The report is quoted as citing the case of financiers Youssef Nada and Idris Nasredin, directors of al-Taqwa, a group Washington believes is a key funder of al-Qaeda.
It is reported that the two men continue to maintain commercial interests and property in Italy and Switzerland, even though they are categorised as terrorist financiers.
The report is quoted as saying that Mr Nada visited Lichtenstein in January and tried to re-register two companies linked to al-Taqwa, despite being banned from travelling under UN restrictions.
Such examples "reflect continued serious weaknesses regarding the control of business activities and assets other than bank accounts," the study is reported as saying.
Mr Nada has denied any links to extremist groups.