Strange patch

[dan620684]

I have noticed this strange patch appear on my Hallway way at bottom of the stairs next to my downstairs cupboard.
Its never been there before and its does not feel damp or have any form of mould near or around it.
I have tried drying it out but it does not seem to go, but has got bigger.
There is no water pipes or anything near the area.
Any help would be fantastic.

Many Thanks

 

[jacko555]

Water from below, if nothing behind or on the other side.
Or, do you have pets?
Looks like a leak to me

 

[dan620684]

Its a concreate floor underneath and there is nothing even near it to leak and nothing on the other side of the door frame either.
Lived in house 8yrs and had no issues before.

 

[jacko555]

What's on the other side of the wall?
What's on the other side of the door?

 

[dan620684]

Its a mid terrace and spoke to nxt door and they dont have any pipework near the wall so nothing leaking their side and the otherside of the door is just a downstairs coat/shoe cupboard.