Barrister who wiped floor with the defence

The QC was widely regarded by those inside the courtroom to have outperformed her defence rival Ronnie Thwaites and to have convinced the jury with her persuasive argument and careful presentation of the evidence.

Her success came despite initial prosecution fears that the jury might be reluctant to convict the Met - particularly in a case related to terrorism - because of potential public discomfort about the use of health and safety laws to govern policing.

Those at the trial say that the turning point came when she discovered that the Met had manipulated a photo of Mr de Menezes to suggest that he bore a closer resemblance than he actually did to 21/7 bomber Hussain Osman.

Ms Montgomery, 49, who has been described by The Lawyer magazine as "quite simply, the best of the bar", was appointed QC in 1996. She represented Sally Clark when the jailed mother was finally cleared by the Court of Appeal of killing her two sons in 2003.

She successfully appeared for Russian tycoon Boris Berezovzky during a 2003 attempt by the Russian government to extradite him and represented other prominent figures including former Chilean dictator Augusto Pinochet.