Told by the police who were there, this is the true story of Britain's biggest bullion heist.

In November 1983, armed robbers stole £26 million worth of gold from the Brink's-Mat security depot near London's Heathrow airport. The nation was gripped as the robbers escaped with 6,800 bars of gold with an equivalent value of nearly £100 million at today's prices.

For the police it was a race against time before the gold was smelted, disguised and sold back on the open market. That much cash in the hands of criminals had the potential to fuel criminal enterprise on an unprecedented scale.

Speaking for the first time since the robbery, Detective Chief Superintendent Brian Boyce, who headed up the investigation, and DC Tony Yeoman reveal the challenges they faced, discuss the strategy they adopted and reflect on the tragedy that unfolded when they staked out Kenneth Noye, one of the men at the epicentre of the gang.

The trail of the missing gold sent police on a cat-and-mouse chase across borders and continents as they tracked a network of corrupt professionals - lawyers and accountants – who helped launder the money through a complex network of foreign accounts and companies, ultimately returning it to the UK to invest in property and drugs.

The story demonstrates how 1980s banking practice, the desire to rebuild London's docklands and a lack of money laundering regulations all aided the robbers and handlers as they transformed the biggest gold bullion haul into cash - and in doing so changed our nation forever.

Palmer is found not guilty. Parry is arrested in Spain. Noye and his associates are convicted, but the police realise the gold was split after the robbery.

Palmer is caught after attempting to escape to Brazil. The police learn that Cooper and Parry have been laundering the Brink's-Mat millions. Cooper is arrested, but Parry escapes.

In Tenerife, Palmer learns he is wanted by the police. Cooper and Parry's plan to move cash across Europe comes unstuck. Noye's murder trial comes to a dramatic conclusion.

The police set up surveillance on Noye and are led to Palmer and more of the gold chain suspects. The resulting raids end in tragedy in Noye's garden.

A chain is set up to smelt the stolen Brink's-Mat gold, sell it back into the market and launder the profits. The police investigation leads them to Kent and Kenneth Noye.

Six armed men have stolen £26m worth of gold bullion from the Brink's-Mat security depot near London's Heathrow Airport. First on the scene are Flying Squad detectives DI Nicki Jennings and DI Tony Brightwell. Back at Scotland Yard however, Flying Squad are not taking the case. Instead, long serving DCI Brian Boyce arrives from counter-terrorism to take charge of the investigation.

Unable to dispose of the bullion, robbery ringleader Micky McAvoy turns to Kenneth Noye, a businessman hiding a criminal sideline. Noye enlists Bristol gold merchant John Palmer to help disguise the gold and sell it back into the market.

Meanwhile, South London wheeler dealer Gordon Parry and the respected establishment solicitor Edwyn Cooper, set about laundering the proceeds from the stolen gold.