Israel has been holding a senior Al Qaeda operative under administrative detention for three years, it has been revealed.

Samer Halmi Abdel Latif Al-Barq, 39, was detained by security forces as he attempted to enter Israel from Jordan via the Allenby Bridge.

Security sources say al-Barq - a Kuwaiti national - is an Al Qaeda operative "with a background in unconventional weapons, with an emphasis on biological weapons," and that releasing him would pose an immediate security threat, as the terror organization seeks to expand its network in the region.

He was apparently involved in planning a large-scale terrorist attack targeting Jewish tourists in Jordan, and had planned to train other terrorists to produce lethal toxins for an unconventional attack inside Israel.

The revelations over his alleged biological weapons links come amid concerns that Al Qaeda affiliates in Syria are attempting to procure bioweapons - and may already have done so.

Responding to a High Court petition on behalf of the terror suspect, State prosecutors charged that his status as a senior Al Qaeda operative leaves authorities with no choice but to keep him in administrative detention in the interests of "regional security and public safety". Under administrative detention, terror suspects can be remanded indefinitely if it is believed they pose a serious security threat.

Al Qaeda's Middle Eastern branches are experiencing unprecedented success, as the Pakistani and Afghan branches have been left decimated by US-led offensives.

Northeast of Israel's borders, instability and escalating sectarian clashes in Iraq, coupled with the ongoing civil war in Syria, have led to an Al Qaeda resurgence there.

Continued political instability in Egypt has provided fertile ground for Al Qaeda-linked groups along Israel's western border with the Sinai Desert, where the Egyptian military has been attempting to root-out Islamist terrorist groups who have being carrying out a low-level insurgency against both civilian and military targets.

Meanwhile, the US government continues to list the terror group's Yemeni branch - Al Qaeda in the Arabian Peninsula (AQIP) - as its most dangerous franchise.