The man who foiled a Yemen-based al-Qaeda "underwear bomb" plot, was a British man of Middle Eastern origin, named as Ibrahim Hassan al Asiri. Who, according to US media, is believed to have been recruited by UK Intelligence agencies to infiltrate the Yemen based Al- Qaeda group. Which is a rare coup for western security agencies.
The agent was sent by al-Qaeda to attack a US-bound plane, but left Yemen and gave the device to US intelligence.
The group planned to attack a US-bound plane with a sophisticated bomb hidden in a passenger's underwear, an updated version of a 2009 device that evaded airport security.
Officials have described the bomb as a "custom fit" device that would have been hard to detect in airport security checks. It was said to have two forms of detonator and no metal parts, making it more sophisticated than the device that failed to explode on Christmas Day 2009.
UK and US officials have declined to comment on the reports. The agent is now reported to be safe in Saudi Arabia while FBI analysts in the US are studying the device.
Written and Presented by Ann Salter