An Al-Qaida plot to bring down an aeroplane using a more sophisticated version of the "underwear" bomb used on Christmas Day 2009, has been foiled by US intelligence, it was revealed today.

The Mk2 is based on the British 'Jockey' 'Y-Front' whereas the Mk1 was built upon the american inspired 'Boxer'.

Significant improvements in comfort (chaffing) and support were reported during trials of the Mk2 - but the real increase in stealth was attributed to the anti-bacterial cotton/polyester mix used to mask odours. This was, ironically, originally developed by Mossad - but dropped for theological reasons.

The 'Scratch'n'Sniff' trigger mechanism, carried over from the Mk1, was easily disarmed by placing a sheet of kitchen foil, dull side down, between the mechanism and the fingernails.

This process, known as foiling, was developed by the FBI following the 2009 lingerie attacks.

Anvil.