Roof Leaks

I have a 1996/7 Discovery and would like to know what causes water to pour in through sunroof handle area (front and back). ? It soaks the back seat (luckily they have waterproof covers) and at the front it not only drips over centre console but runs down inside of screen. This does not happen all the time but mainly after a major down pour.
I have checked round sunroof area with window open but cannot see anything obvious. Are there any drains that can be clenaed out?. If they are clear what can I check next.??? Answers on a post card please.....to Steve B. Thanks

Steve, do a search on leaking sunroofs before the lynch mob get yer..!

Thanks for the tip, forgot about searching. Dont think the the lynch mob know where I live but I'll keep me head down just in case..

When mine is parked on the drive bonnet down hill nothing comes in, when its parked pointing up hill the rain comes in, waits till I drive off round a corner then a water fall comes out of the relevant hole for the seat belt shoulder strap, like most things on a landie once you know how to avoid it happening you learn to live with it.

leaking sunroofs are part of owning a disco, search out leaking 'windscreens' and 'alpine lights' as well, been covered on 'ere more times than: 'I fink I want some mud tyres, whadya guys reckon to these'...!!!