An army of white-coated scientists equipped with the latest technology will make it harder than ever for dope cheats to avoid detection at the London Olympics, organisers warned on Thursday.

Unveiling its high-security WADA-accredited laboratory in Harlow, half an hour north of the Olympic Park in east London, organising committee LOCOG outlined the gargantuan size of its anti-doping operations.

One in two competitors will be tested during the Games, including all those who win medals, with 150 highly-trained boffins working 24 hours a day, seven days a week to process more than 6,250 bar-coded bottles of urine and blood arriving from the various venues.

That equates to 400 tests each day, a higher number than any previous Olympic Games.

This is all about the integrity of the Games, Britain's Minister for Sport and the Olympics Hugh Robertson told reporters during a tour of the various labs that would not have looked out of place on the set of a James Bond movie.

People there in person or watching in front of the TV want to know that it's a true and fair contest, he said.

Doping is one of the two main threats to the integrity of these Games so it's incredibly reassuring that we have the most up to date, modern testing lab that exists anywhere in the world.

Of course we can't guarantee that they will be a drug-free Games but we have very best system to try and catch anybody who even thinks of cheating and that's a very powerful message to send out around the world.

London 2012 partner GlaxoSmithKline (GSK), the pharmaceutical giant, have provided the facility, roughly the size of seven tennis courts, at a sprawling, razor-wire guarded compound.

LOCOG will have 1,000 staff on duty there during the Games, with the specialist testers working for Professor David Cowan, who runs the Drug Control Centre at King's College London.

These laboratories are the most high-tech labs in the history of the Games, analysing more samples than ever before, said Cowan.

Athletes whose A sample tests positive will be notified within 24 hours, after which they can ask for their B sample to be analysed.

Organisers say the chances of contamination and erroneous results are virtually impossible thanks to a barcode identification system never previously used at an Olympics.

The complex processes used at the laboratory will be able to detect around 240 illegal substances.

London is the first Olympics to have its anti-doping programme sponsored by a pharmaceutical company, but GSK played down any concerns that it represented a conflict of interest, saying the lab would be independently operated.

Our involvement is the support and delivery of the facility; we have no role in the testing process, GSK chief executive Andrew Witty told reporters.

We're not involved. You can be 1,000 percent reassured that there's no overlap, no conflict.

(Reporting by Martyn Herman, editing by Alan Baldwin)