A judge has praised Kent police officers for the "high grade" investigation into the £53 million Tonbridge robbery.

Mr Justice Penry-Davey, who conducted the Old Bailey trials, commended Detective Chief Inspector Mick Judge and his team at Maidstone Crown Court.

The judge said: "I don't suppose anybody who has been involved in the Tonbridge robbery in one way or another will ever forget the experience.

"Perhaps most of all where there is any risk of a crime, a major crime such as this being spoken of as victimless, most of all those who will not forget it are those employees of Securitas who were victims of this crime and some of whom are still suffering the after effects and will continue to do so, perhaps for the rest of their lives.

"That, however, is some measure of the importance of a high grade investigation and I said at the conclusion of these series of trials this about the investigation; it is invidious to identify individual police officers and others concerned with this vast and lengthy investigation but I would like to commend those involved with it for the speed, intelligence and thoroughness with which a very high profile and important investigation has been pursued.

DCI Judge joined Mr Justice Penry-Davey, Mr Justice Bean and Judge Andrew Patience QC at their bench to receive the commendation. Also present were Supt Mark Powell, Det Sgt Andy Nicoll and Det Con Alastair Worton.

Six men were jailed for their part in the terrifying raid on the Securitas depot in February 2006, Britain's biggest ever cash heist.

An armed gang kidnapped the wife and child of depot manager Colin Dixon from their then Whitstable home to force him to gain access to the high security depot, which stored cash from Bank of England reserves.

They then held staff hostage at gunpoint while they loaded cages stacked with cash into lorries before escaping.

After the commendation, it was announced that Mr Justice Penry-Davey was retiring and would no longer be the presiding High Court judge on the south east circuit.

"This is a historic, rare, sad day for the south east circuit," said Mr Justice Bean. "He has been greatly esteemed and respected on the circuit."