A former British Airways computer expert has been found guilty of conspiring with a wanted terrorist to blow up a plane.

Rajib Karim, 31, used his position at the airline to plot an attack with Anwar al Awlaki, a notorious radical preacher associated with al Qaeda.

The privately-educated Bangladeshi national, who moved with his wife and son to Newcastle in 2006, led a double life, jurors heard

He was "committed to an extreme jihadist and religious cause" and was "determined to seek martyrdom" but hid his hatred for Western ways from colleagues.

His techniques for siphoning information from BA were described as like a "John le Carre-style" plot.

He used his access to the airline's offices in Newcastle and at Heathrow to encrypt confidential information in spreadsheets and also held a secret meeting with fellow Islamic extremists at Heathrow.

But Karim, described as "mild-mannered, well-educated and respectful" by his colleagues, never aired his extreme views.

When he was arrested while sitting at his desk in BA's IT department in Newcastle in February last year, his colleagues were left shocked.

While in Bangladesh, Karim was lured into becoming an avid supporter of the extremist organisation Jammat-ul Mujahideen Bangladesh (JMB) by his younger brother.

But their plan to live in an Islamic state was put on hold when Karim moved to England in December 2006, fearing his son was dying of cancer.

In 2009, he began communicating with al Awlaki from his home and communicated in code with JMB supporters in Bangladesh.

As he became more extreme in his beliefs, he conspired to blow up a US-bound plane with al Awlaki, who is believed to be hiding in the mountains of Yemen.

Police arrested Karim after recovering a small white laptop from his home and a hard-drive they later found were used to plan the conspiracy.

They declined to discuss what led them to Karim but it is understood he was under surveillance for several weeks.

Karim convicted at Woolwich Crown Court, south east London, of four counts of engaging in preparation for terrorist attacks.

He will be sentenced on March 18.