Goodmorning, I need help with this tricky one please:

my mechanic has been working on it for days without success! a few weeks ago my 1999 Disco 2 V8 has developed a rather loud mechanical "clunking" sound, seemeingly from the rear end: when turning sharply (particularly when applying the brakes) you can hear this rather loud "clunk clunk clunk". The sound is of short duration and it seems to be originating from the rear end (drivers side?). I have taken the car to my Land Rover specialist who seems to be a bit bamboozled by it: he kept the car in the workshop for days and rapidly ruled out the obvious, such as shocks, diff noise or transmission. He then proceeded to change some bushes in the cornering enhancencement system...no success. He now thinks the sound could be coming from the gas strut in the "anti-rolling" system (??). I would be very greatful if anyone could come up with some suggestions regarding this...it's driving me mad!! Many many thanks in advance,

Nick C.