Damp from adjoining wall?

[solfer]

Hi,

Our shower was fitted & tiled just over 2 years ago, and I've just noticed the bedroom wall, which adjoins the tiled wall of the shower, has a nasty case of damp. It was hidden behind a computer desk, so may well have been getting worse over time..

The damp area, from the middle of the wall downwards, is in the exact same position where the shower tiles get soaked twice a day.

The tiles are natural stone, and were given a coat of sealant when first fitted, but I'm thinking that maybe the water is still soaking through the tiles and into the wall.

Any suggestions? Should I reseal the tiles before doing anything else?

Thanks,