A new piece of information is available following a Freedom of Information Act request to Thames Valley Police by Brian Spencer.
There was 111ml of water left in the 500 ml Evian bottle of water found at the scene on Harrowdown Hill.
In other words, even if one assumes that the bottle was full when he started on the walk, the "suicide hypothesis" requires you to believe that David Kelly swallowed 29 co-proxamol tablets using no more than 389ml of water.
And that, despite major blood loss and developing thirst, David Kelly didn't drink the water remaining in the bottle of water.
I don't believe it. And, I suggest, you shouldn't believe it either.
Brian's post is here: The water left in the Evian bottle.