HALF of all London Olympics competitors will be tested for drugs in what is being billed as the biggest anti-doping operation in the history of the Games.

And Hampshire Olympians such as diver Pete Waterfield, cyclist Dani King and rower James Foad will definitely be tested if they can land a medal – be it gold, silver or bronze.

A team of 150 scientists will take more than 6,000 samples between now and the end of the Paralympic Games on September 9 in a bid to ensure the Games are not tainted by disqualifications and scandals like those which have happened in the past.

The London 2012 anti-doping laboratory, operated by GlaxoSmithKline (GSK), Locog and King's College London, will be in operation 24 hours a day, seven days a week.

Among those tested will be every competitor who steps on to the medal-winners' podium.

UK competitors Phillips Idowu, Beth Tweddle, David Weir, Graham Edmunds and Marlon Devonish are to appear in a television and billboard advertising campaign run by GSK to highlight the importance of the anti-doping operation and the science behind it.

Sprinter Devonish, who won Olympic gold in the 4x100 metres relay at the 2004 Athens Games, said: “Winning an Olympic medal is the best feeling in the world and as an athlete it’s so important to know that anyone who stands on the podium has got there through their own hard work and dedication, not by doping.”

Testing will take place at the London 2012 lab in Harlow, Essex, with the scientists led by Professor David Cowan from the Drug Control Centre at King's College London.

More than 1,000 people will staff the lab, with up to 400 samples tested every day for more than 240 prohibited substances.

Drugs have been in the spotlight after sprinter Dwain Chambers and cyclist David Millar had their British Olympic Association lifetime bans for drug-taking overturned by the Court of Arbitration for Sport (CAS).

Both will compete at the London Games.