Only a lack of technical expertise is stopping al-Qaeda from carrying out a chemical or biological attack, a United Nations report has warned.
Al-Qaeda was blamed for the 11 September 2001 attacks
The report said al-Qaeda ideology had continued to spread, raising the spectre of further attacks.
Sanctions against al-Qaeda were proving difficult to implement fully, the UN panel of experts said.
And they warned that United Nations member states were not doing enough to crack down on terror groups.
"Many of al-Qaeda's sources of funding have not yet been uncovered or blocked," the report said.
"Al-Qaeda continues to have access to funds through charities, deep-pocket donors and from business and criminal activities, including the drug trade."
Michael Chandler, who chairs the UN monitoring group, said he did not think a biological attack was necessarily imminent. But he told the BBC's World Today programme the signs were there that al-Qaeda wanted to use such tactics.
"It is probably the fact that they are looking for some technical means of dispersion rather than actually the stuff itself," he said. "The ingredients are available if they want to get hold of them."
Call for tougher rules
Until now the monitoring committee has relied on UN member states to volunteer information about how they are limiting the activities of al-Qaeda and associated groups.
But fewer than half of all member states are co-operating and even the quality of the information provided by those states is being questioned, the UN report said.
It called on the UN Security Council to pass a resolution that would compel nations to co-operate more fully.
"Without a much tougher and more comprehensive resolution... little or no progress will be achieved with regard to the sanctions regime imposed on Osama Bin Laden, al-Qaeda, the Taleban, their associates and associated entities," the report said.
The report said that while great importance had been attached to limiting the movement of al-Qaeda operatives between countries, so far not a single UN member state had presented any evidence of the arrest or detention of such people at border crossings.