A gang who plotted to steal £33m in diamonds, cash and gold from a Heathrow warehouse had been given inside information, a court heard.
Eight masked men reversed a Mercedes van through the shutters at the Swissport cargo warehouse on 17 May last year, threatening staff with hockey sticks and batons just as £15m worth of Peruvian gold was about to be unloaded into a vault.
Kingston Crown Court heard the gang struck at 9.57am when the gold was at its "most vulnerable", straight after it had been taken out of a Brinks-Mat van and had its shrink wrapping removed.
The jury was told that some £18m worth of diamonds and bank notes had already been placed in the strong room after arriving on a previous flight.
John Kelsey-Fry QC, for the prosecution, told the court: "They were well-informed. They knew where to hit, when to hit and they knew what they were looking for."
But the barrister added the raid was foiled by police, who were lying in wait: "Unfortunately for these robbers, the police were ahead of the game and a large number of armed police officers were on hand and stormed the warehouse shortly afterwards."
He said: "This robbery team needed and clearly had the benefit of an inside man, someone who worked at Swissport, who could provide them with the necessary information."
Mr Kelsey-Fry told the court one of the four men in the dock worked at Swissport and is alleged to be the insider. All four plead not guilty to a charge of conspiracy to rob between 1 March and 18 May last year.
The QC said seven of the eight robbers have pleaded guilty to conspiracy to rob with one man still at large.
He revealed six of those eight were immediately arrested in the warehouse itself, the seventh escaped by hijacking a lorry "which resulted in a high-speed chase to the robber's own home where he was arrested".
And he added: "The four men in the dock are not said to have been amongst the eight I have referred to. What is said is that each of them was party to the plotting and planning and facilitating of this attempted robbery. All were party to the conspiracy."
The trial continues.