IN PICTURES: Fake ambulance drugs trial: Dutchman found guilty of smuggling Class A drugs into UK

Prosecutors said "right-hand man" Leonardus Bijlsma, was part of a "lucrative criminal conspiracy" concealed from border officials with the aid of bogus paramedic uniforms and fake patients on crutches.

Bijlsma, aged 55, of Hoofddorp, Amsterdam, now faces a lengthy jail term after denying the charges throughout a two-week trial at Birmingham Crown Court.

Two other men from Holland; Olof Schoon, said to be the conspiracy's central player, and Richard Engelsbel had already admitted the conspiracy charge and will be sentenced alongside their compatriot next week.

A fourth man, 28-year-old Dennis Vogelaar, of Vijfhuizen, Amsterdam, was acquitted by the jury of smuggling class A contraband.

All the men were all arrested near a scrapyard in Smethwick, West Midlands in June this year, after Schoon and Bijlsma had driven to the rendezvous in a hire car.

A Mercedes ambulance driven to the scene by Vogelaar and Engelsbel was also seized and found "rammed" to the roof with cocaine, heroin and ecstasy, according to the Crown.

When officers from the National Crime Agency (NCA) broke open the rear of the vehicle they found seven hides concealed behind riveted metal plates into which were neatly stacked and wrapped hundreds of packets of drugs.

In all there was 193kg of cocaine with a street value of more than £30 million, and 74kg of heroin worth £8 million in individual deals.

Officers also found thousands of ecstasy tablets and 2kg of MDMA crystal powder.

Opening the case, Robert Davies, prosecuting, detailed how Dutch authorities tipped off by British colleagues uncovered "a fleet" of similarly adapted ambulances back at two yards in the Netherlands believed to have been used to transport a "staggering" amount of contraband.

Mr Davies described it as "an absolutely enormous amount of class A drugs".

Further analysis revealed that between the vehicles, at least 45 trips were made in 14 months to locations in Essex, London, Manchester, Merseyside, West Yorkshire and the Midlands, with the final trip in June.

It is estimated that the operation may have seen £420 million in high-purity drugs smuggled into the UK, with an estimated street value worth four times that amount.

Bijlsma, aged 55, had denied a smuggling conspiracy charge throughout their two-week trial at Birmingham Crown Court, claiming he was merely an illiterate handyman.

As the guilty verdict was read out, the heavy-set man clasped his hand in front of him and blinked once.

Vogelaar was cleared by a jury after the window cleaner and qualified HGV driver told the court he had no idea the contraband was in the back of his vehicle.

Relief was writ large on his face as he was told he was free to leave the court dock, a free man.

Jurors were told 38-year-old Schoon, said by the Crown to be the conspiracy's "central player" and Engelsbel, had already pleaded guilty to conspiracy to smuggle drugs into the UK.

The three men will all be sentenced on December 7.