As international attention in Syria focuses on efforts to dismantle the Assad regime's chemical weapons stockpile, British experts are warning of another, potentially more lethal threat.
Experts from the Henry Jackson Society (HJS) have issued a stark warning over what they say is the "clear and present danger" of Al Qaeda gaining possession of the Assad regime's stockpile of biological weapons, claiming to have substantial evidence that Al Qaeda-linked groups may already have possession of toxic agents.
Unlike chemical weapons, which utilize chemical agents to poison victims, biological weapons make use of diseases, toxins and other contagious agents. Biological weapons have the potential to kill far greater numbers, and are also far harder to detect or protect against.
Both are banned under international treaties, but the Syrian government possesses active programs in both fields. However, whilst the use of chemical weapons during the Syrian civil war has been seen on numerous occasions - most notably, but by no means exclusively, during the August 21 attack which killed more than 1,000 people in a number of Damascus suburbs - biological weapons have not been used by either side.
That is likely because bioweapons are notoriously difficult to control or contain.
But the HJS report, released on Tuesday, says that jihadists in Syria are actively seeking to gain control of the regime's biological weapons' stockpile and, chillingly, suggests they may already have done so.
The report claims that the Assad regime is losing control of its bioweapons arsenal, in part because it was never centrally-controlled in the way the country's chemical weapons stockpile has been.
"Unlike chemical weapons, maintained in military designated stockpiles which are generally identifiable and which Assad maintains command and control over, the structure of Syria's biological warfare programs are latent, compartmentalized and spread across its remaining bio-pharmaceutical infrastructure. The programs are designed to be highly agile to allow swift production if required."
Worryingly, the report suggests that the Al Qaeda-linked Nusra Front may already have possession of "biological pathogens or weaponized agents either of which would pose a threat to the international community."
It points to the widespread looting of bio-pharmasuitical laboratories throughout the country, and cites a "credible eyewitness" as claiming to have personally witnessed "a looted pharmaceutical laboratory," near Aleppo, where Syria's biological weapons program is concentrated, "which was probably a cover for a biological weapons production site."
The fact that a Malaysian Al Qaeda operative named as Yazid Sufaat, identified as "Al Qaeda's primary biological weapon expert", was arrested in February as he attempted to enter Syria, was said to indicate the clear interest that the group has in developing such a program in the country.
Other Al Qaeda branches, most notably in Yemen and North Africa, have previously attempted to obtain such weapons, and the group's founder, Osama Bin Laden, had expressed an interest in them prior to the infamous 9/11 attacks.
While the report does not cite any clear and definitive evidence of Al Qaeda physically possessing biological agents, the circumstantial evidence paints a fairly alarming picture.
On the other hand, analysts will find some solace in the fact that neither Al Qaeda nor any other terrorist group has successfully manufactured and deployed biological weapons to lethal effect.
But HJS's Associate Fellow Dr Bellamy van Aalst, a former EU and NATO bio-defence consultant, warned against complacency, in light of the relative availability of already-weaponized and readily-deployable biological weapons in Syria.
“Establishing the extent to which Assad may have developed biological WMDs is extremely difficult, given that their production is indistinguishable from benign biological lab processes.
“But this is certainly a risk to which we should not turn a blind eye. If Assad has been developing biological weapons, as the evidence suggests, and if those weapons fall into the hands of extremists, global health security could be in grave danger.”