Trials cost 14 times the Heathrow robbery haul

The final bill for bringing the Heathrow robbers to justice is estimated to be at least £25 million - more than 14 times the amount stolen.

Here is a timeline of events leading to the first serious criminal trial in England and Wales to be heard without a jury:

* July 2003. Police receive intelligence that a raid on the Menzies World Cargo warehouse at Heathrow Airport is being planned and begin a surveillance operation.

* February 6 2004. Six armed robbers raid the warehouse at gunpoint, tying up 16 members of staff, and shooting at one as he tries to escape, before making off with £1.75 million in currency. The cash has not been recovered.

Ringleader John Twomey is arrested later that month.

* March 2005. Twomey goes on trial before Judge Jeremy Roberts at the Old Bailey with a number of other men but is taken ill after it opens and cannot continue.

* July 2005. Peter Blake arrested.

* May 2006. Barry Hibberd arrested.

* March 2007. Twomey faces second Old Bailey trial, alongside Blake and Hibberd. Meanwhile, Glenn Cameron is arrested in a caravan park in Cornwall.

* August 2007. The jury, which has been reduced to 10, retires to consider its verdicts and sends a note to Judge Roberts indicating a "very strong majority decision" of 9-1, which the judge later says is adverse to the defendants.

But the judge decides not to give them a majority direction until after the Bank Holiday weekend - after which one juror refuses to return, saying he is stressed.

The jury is unable to reach a verdict and is discharged. The defendants are granted conditional bail.

* June 2008. Third trial begins, again before Judge Roberts at the Old Bailey. Cameron is now in the dock alongside Twomey, Blake and Hibberd.

* December 2008. Prosecution tells the judge of evidence that approaches have been made to two members of the jury. Jury discharged and trial stopped.

* March 2009. Mr Justice Calvert-Smith orders that the evidence of jury nobbling should remain withheld from the defence.

But he decides the case can still be heard by a jury protected by a £1.5 million package of security measures involving 32 police officers.

* June 2009. The Court of Appeal overturns the decision, deciding that neither this package nor an even more expensive one sufficiently addresses "the potential problem of interference with jurors through their families".

It orders a trial without a jury.

* January 2010. The fourth trial begins before Mr Justice Treacy at the Royal Courts of Justice. Sam Stein QC, for Hibberd, remarks: "We are breaking history."

* February 2010. Blake absconds for a week, later explaining that he wanted to get some clothes. He is remanded in custody and the case is moved to the Old Bailey shortly afterwards.

* March 2010. The judge retires to consider his verdicts.

* March 31. All four defendants found guilty.