Hi everyone I'm pretty excited. After a long time searching I found a way to get higher resolution textures working in game. I've tested this with textures of up to 2048x2048 (2k) compared to the original resolution of 256x256. Just a warning this will increase your loading times.

Here's some screenshots:
http://imgur.com/a/bj90w

First

• Download this program called TexMod from: http://texmod.googlecode.com/files/texmod.zip
• The program's homepage can be found: http://code.google.com/p/texmod/
• Extract the zip file using winrar or the default windows unzipper to a location of your choosing.

To extract the textures you want to edit:
Start Texmod.
There you can find some Tabs :

- Package Mode
- Logging Mode
- Package Build

Now you press on the second tab called "Logging Mode".
You will find a black frame with a little folder in it on the left upper side,
click on it. A window will appear. Choose the Game .exe
file of the Game you want to edit.
Under the tabsbar there are some options.
tab :
-Draw Control and Texture Info
-Show Texture on upper left Corner
-Replace Texture (with a green Texture)

As the output format choose .dds (which are the best ones)
and "Log with ENTER".
As the output folder take the one you want to have the Textures in.

Press RUN.

To edit the textures in Photoshop you will need to download the 32 or 64 bit version of the .dds plugin (depending on your Photoshop version) from: http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop

To load the textures in-game
Press the package build icon and direct it to your log file created when you extracted the textures and choose a file name that you want.
Press build
Select package mode and target the Call of Cthulu application
Select the package/s you just created then press run at the bottom.

Next steps
I decided to use this new found knowledge to make a high resolution texture pack for the game. I haven't got very far yet but would be extremely grateful if anyone would like to help me as I'm not too great at texturing some objects. I've been working on the Asylum intro and first level.

Very cool! I edited the links so they work

Much appreciated

Fantastic! Look forward to seeing the results