By Mark White, Home Affairs Correspondent
A south London man may have been planning a Mumbai-style mass casualty attack when he was arrested by police in the capital, an Old Bailey jury has been told.
Erol Incedal, 27, has already been convicted of "possessing documents of use in terrorism".
A retrial on a charge of "preparing acts of terrorism" has begun at the Old Bailey, with the jury told that much of the evidence will be heard in secret on the grounds of national security.
A Court of Appeal ruling in June last year stated that the "core of the trial" is to be held behind closed doors.
Only the reading of the charges, the swearing in of the jury, part of the prosecution opening and a small part of the evidence will be heard in open court.
The judge, Mr Justice Nicol, told the jury of seven men and five women: "This is a retrial of the evidence which the defendant faces. He was previously tried on two counts last year - he was convicted of one count, possessing information of use in terrorism.
"It does not necessarily mean he is guilty of the present offence or that he was or is a terrorist.
"The jury could not agree on the charge he now faces, that is why there is a retrial. Such retrials do happen from time to time... if you are aware of any reports of the previous trial, put them out of your mind."
Beginning his opening remarks, prosecutor Richard Whittam QC told the jury they would hear evidence that the defendant was "actively engaged with another, or others who were abroad".
He said: "The prosecution's case is that such engagement was for an act or acts of terrorism, either against a limited number of individuals or an individual of significance."
Mr Whittam said that Incedal might also have been planning "a more wide-ranging and indiscriminate attack such as the one in Mumbai in 2008 when young men armed with a number of weapons, including automatic rifles such as Kalashnikovs, killed 164 people and wounded over 300 more".
The defendant was arrested in a car along with another man, Mounir Rarmoul-Bouhadjar, while the pair drove around east London on 13 October 2013.
The jury was told that Rarmoul-Bouhadjar has previously pleaded guilty to possessing a bomb-making guide.
In other remarks to the jury, Mr Justice Nicol said: "While this trial is no different from others in many ways, it does have some features which are unusual.
"The usual way justice is administered is in public... the trial can be reported.
"Some of this trial will be conducted in that way. However, there will be other parts of the trial which will be in private and the public will not be able to attend.
"A limited number of journalists will be able to attend but will not be able to report on the proceedings.
"There's a final part, from which even those journalists are excluded."
He warned the jury that they faced jail if they discussed the case outside the court.
"It is important that you do not talk about the private proceedings to anyone outside your number, with the possible consequences I mentioned earlier... to break these simple rules will be a contempt of court."
