Can you mount an img file side a docker container

I’ve been trying to download and mount an img file inside a docker container to add some files to a partition then unmount.
I can run my script through fine on Ubuntu itself but am hitting some limitation with mount when trying to run the same script under docker.

I pre-create the /mnt/img folder and then calculate the offset using “fdisk -l file.img” and multiply by 512 to get the offset shown below.
The mount command itself is;

mount file.img -o loop,offset=4194304 /mnt/img

I just get the following message back;

mount: /mnt/img: mount failed: Operation not permitted.

I have tried using --privileged and --cap-add=SYS_ADMIN and finally with disabling apparmour in the underlying Ubuntu host machine without success. Is this just not possible?

Can you show the docker and mount command (inside or outside container?) you try to execute?