Four people jailed for a £1.75m armed robbery at Heathrow Airport will have to wait to discover if an appeal against their convictions can go ahead.
John Twomey, Peter Blake, Barry Hibberd and Glenn Cameron were convicted in March in a trial without a jury, which they claim was "unlawful".
The men were found guilty in relation to a raid at the Menzies World Cargo warehouse in 2004.
Appeal court judges reserved judgement in the case heard at the Old Bailey.
The Lord Chief Justice, Lord Judge, sitting with Mrs Justice Rafferty and Mr Justice Roderick Evans, said: "We wish to take time to consider our decision."
It was the first serious criminal trial to be held without a jury in England and Wales for more than 350 years after three previous attempts to try the case with a jury had failed.
Twomey, 62, of New Milton, Hampshire, described as the ringleader, was jailed for 20 years and six months while Blake, 57, of Notting Hill, west London, was jailed for life with a minimum term of 10 years and nine months.
Cameron, 50, also of New Milton, was jailed for 15 years and Hibberd, 43, of Shepherds Bush, west London, was sentenced to 17 years and six months.
Their appeal centred on the secret evidence of alleged jury tampering which had led to the trial being heard by a judge alone.
It was decided at the time that this material could not be made public or disclosed to defendants because of its sensitivity.
But John Aspinall QC, for Twomey, said there had since been an "essential change in the law" about such disclosure after a ruling in a case concerning the use of control orders.
This means that a "core irreducible amount of material" would have to be given to a defendant which, though not all the material, could be an "edited, summarised or gisted" version.
He said that in this case there had been no disclosure by the Crown about the jury tampering, either at the trial or during a previous Court of Appeal hearing which decided it should be heard without a jury.