TD4 fuel leak

Okay so I bought a 2002 freelander td4 about a week ago and have noticed a fuel leak dripping from under the tank. Checked the fuel pump and it's all wet there too.
The bloke I bought it off said he changed the fuel pump last year so I thought I'd take it out and check the seal was seated etc. Everything seems fine on the fuel pump nothing obvious wrong.
It only leaks when I've got more than 2/3 of a tank.
My next suggestion is maybe a hair line crack in the top of the tank? Maybe from where he's pushed down or over tightened the ring? However this is an expensive and pain of a job!!
Any more suggestions as to what it could be and has anyone attempted a fuel tank change?

Thanks

Ouch!
Sorry about that, 'fraid I can't help but hopefully someone else can. If you need to take the fuel tank cradle out apparently it isn't that big a job but you might be as well replacing it at the same time. They rot away to dust in no time so it will need changed in a year or two anyway.

Good luck with it.

The cradle has been changed a couple years ago so I'm hoping that it will be okay and won't need doing.