Chimaera drive shaft rattle

[Bart]

Ever since I bought it (about 4 months ago) it has had a rattle coming from the rear over rough ground. Initially suspected anti-roll bar bushes or shock absorber bushes. Sounds like that kinda noise. Just had a proper old look underneath today and all looks fine.

I can't feel any radial play in the drive shafts but the axial movement causes a noise similar to the one I am hearing. There is no knocking or rumbling. Could the noise be caused by the normal movement of the driveshaft as suspension the angles change?