Is it safe for me to remove this doorway under the stairs?

[Riisargh]

Hello everyone,
I'm currently in the middle of renovating my kitchen and dining room.
I'm wanting to remove the door frame that sits below the stairs. It doesn't seem to have a lintel that goes across in to the brick either side. However, there are 3 bits of wood that look like support or something? Or maybe they're there for the fake wall?
I'm hoping to get rid of it in order to put shelving on the right side to make in to a kind of storage/pantry to be included in to the kitchen and not as wasted space.
I've included some photos for reference.
If it's not supporting, how are the stairs supported? So I have a better understanding?

[GALLERY=media, 102995]15621633119027969203418228132562 by Riisargh posted 3 Jul 2019 at 3:15 PM[/GALLERY][GALLERY=media, 102994]1562163281922954845145466492028 by Riisargh posted 3 Jul 2019 at 3:15 PM[/GALLERY][GALLERY=media, 102993]15621632503936414777284168429510 by Riisargh posted 3 Jul 2019 at 3:15 PM[/GALLERY][GALLERY=media, 102992]15621631967235846810741063748763 by Riisargh posted 3 Jul 2019 at 3:15 PM[/GALLERY][GALLERY=media, 102991]15621631654737329901848212793171 by Riisargh posted 3 Jul 2019 at 3:15 PM[/GALLERY]

 

[blup]

It's difficult to tell.

Is the staircase straight, or is there a mid landing.

Can you post pics showing the staircase?

Blup

 

[John D v2.0]

the 3 bits of wood are just to hold the laths up before plasterboarding. It's basically a stud wall.
The stairs would have wedges and blocks from the stringers at either side and would be basically self supporting.
We knocked out pretty much exactly this setup (below the winders) between the upper newel post and the wall, directly below the top step, and nothing has moved.

 

[Riisargh]

Thank you very much. It did turn out not to be supporting. I had someone come round to check. It is now out and looking more spacious in that area.

Thank you for your replies.