Your link is showing as a malicious webpage. If you really need advice about the drywall, please post a pic in the comment section so others can answer your question.

I was able to safely open it. Here is the pic:

have you addressed the mold and why there is moisture getting into the walls? I have a 100 yr old concrete house which had eroded and absorbed water so did a lot of research on the topic - if you have conventional latex or oil house paint on the exterior it may be trapping moisture- you would need something breathable on the exterior (I used potassium silicate coating aka mineral paint) and possibly on the interior as well. You need to keep water out, but vapor from outside and from inside (from laundry,cooking) needs to pass through freely.

Re: what it is, I m sorry if this soundss snarky but you would need to tell us what it is. It looks like plaster or drywall, or possibly they did some kind of cementitious coating on the inside directly onto the concrete? Can't tell from the pic.

thank you very much for your help. It is a ground floor flat which doesn't see a lot of light and if I don't constantly ventilate I get mold and sometimes wetwalls.

It looks like cement coating to me but I'm not sure. is there a way to tell the difference between cement and plaster?