The leader of a university Islamic society flew into a British airport with bomb-making instructions and blueprints for missiles in his luggage, the Old Bailey was told yesterday.

Police also found a letter from Yassin Nassari’s wife in which she encouraged him to become a terrorist and offered herself as a “martyr”, alongside their baby son.

Detailed instructions of how to build rockets and explosives, and recordings of lectures by extremists, were discovered on a computer hard-drive in Mr Nassari’s bag. He and his wife, Bouchra el-Hor, 24, were stopped after landing at Luton airport on a flight from Amsterdam in May last year.

Aftab Jafferjee, for the prosecution, said: “Nassari was going to engage in what he and others like him would call jihad, but what the law describes as terrorism. His wife was not only aware of his intention, but positively encouraged it, despite the fact that his actions would almost certainly result in his death and leave their son without a father.”

Mr Jafferjee said that an al-Qassam missile, of the type used by the Palestinian group Hamas, could have been manufactured from the instructions found on Mr Nassari’s computer.

The computer also contained the recipe for a highly explosive material, and articles including Virtues of Martyrdom in the Path of Allah.

Ms el-Hor, a Dutch citizen who lives with her husband in Ealing, West London, denies failing to disclose information about acts of terrorism. Mr Nassari, 28, who was born in Britain, denies possessing an article for the purposes of terrorism and possession of a document of record likely to be useful to a person committing or preparing an act of terrorism.

He claimed to be the religious leader of the Islamic Society at the University of Westminster’s campus in Harrow, North London.

The couple married in March 2005 and moved to Syria, where Mr Nassari worked as an English teacher. His wife returned to the Netherlands to have their child in November that year, and was joined by her husband in April last year.

They were described by Mr Jafferjee as having “mindsets beyond ordinary understanding and possessing a chilling resilience”. He said that the police had discovered documents about landmines and a vast amount of material relating to the “gruesome application of jihad in a variety of conflict zones”. Mr Nassari, he added, “also had a variety of material regarding jihad fitness training, martial arts and hand-to-hand combat”.

Recordings of lectures by radical clerics included one entitled “We are terrorists and terrorism is an obligation”. The student of cognitive science disappeared between 2002 and 2003. When he returned to university he had abandoned his Western clothes for Islamic dress.

Mr Jafferjee said: “He was now sporting long robes and wearing head-wear. He claimed he was the religious leader of the Islamic Society at the university’s campus in Harrow. To put it bluntly, he was now radicalised. Attention to his academic obligations was intermittent and he did not achieve his degree.” He said other material relating to Mr Nassari’s degree and clothing business proved that he was responsible for the content of the hard-drive.

The trial continues.

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