I rang Duresta and they told me the fabric was a 50/50 mix of viscose and velicren weave. I read what you lot were talking about in the other running suite thread and the link to the other site and concluded that a gentle wet treatment could be done.
As I'm not a CC and have no equipment I used vanish soap bar which contains enzymes and no bleach. Soap was applied with cold water on a damp micro fibre cloth and rinsed with worm water on same cloth then dried with a hair dryer....and has come up like new.