On Wednesday, prosecutor Waters said Akbar was secretly recorded discussing possible targets with Khyam.

"The biggest nightclub in central London, no one can put their hands up and say they are innocent -- those slags dancing around," Waters told the court he had said.

Days later, Akbar was overheard fretting to his wife about two missing CDs with "Transco" written on them.

"Transco, you know what -- if we got raided today we're finished," he said, according to Waters.

National Grid Transco owns and operates the electricity and high pressure gas systems in Britain and Waheed Mahmood was employed by one of the firm's two principal contractors at the time, Waters said.

Later, the court heard that Amin had told UK police in an interview last year that his superior in a Pakistan training camp had asked him to help contact the Russian mafia about buying a radioisotope bomb.

Amin told police he did not think it was a genuine plot adding it was unlikely "that you can go and pick an atomic bomb up and use it," Waters said, adding nothing appeared to have developed out of the plan.

Even so, he argued that it showed Amin's importance to the militant organisation.

The trial continues.