In the news

Not really read anything except the gruniad article, but:

didn't they see him walking to his apartment?
according to the article he was last seen shopping 8 days before his body was discovered and also they described the body as badly rotten (or something like that)

also a human body isn't what i'd call light, its called dead weight for a reason
in the same article he was described as 'slight'.

I'm not saying it would be easy, but in my opinion it's more likely that he died somewhere else and then was dumped rather than he climbed into a hold all in his bath, locked him self in it and then sat there to die.