The interesting bit is what protocols are they using?
In an earlier life as a union leader, we discussed this with DOT, when the US FAA anounced that they had the rights to test anyone associated with flights from OZ to the US.
When asked what safety was built into the checks we drew a blank. We suggested as a minimum we use the same protocol as sports checks which includes 2 sealed samples, one for them and one for you. That way if their sample comes up positive you have evidence if their sample is tampered with. The Yanks didn't like that idea and suggested that we didn't trust them.
Nothing then came of it then, but I think the same still stands. Sports testing is down to a fine art and I think the same process must be given to us. The sportspersons are only playing games, we are dealing with reality.
Wunwing