flash will not turn off on iphone 4

Welcome to the discussions,
try to restore "as new iphone" without using the backup afterwards to get your data and settings back.
Try to use the camera without installing any other apps than the default programs. If your problem persists, get your phone serviced.
If no problem, install your 3rd party apps again. If the flash will not work as expected after that, one of the 3rd party apps may cause this.

I have tried system restore, without backup and tried to use camera with flash and then try turn it off at the recording. It won't turn off.

This issue is really bugging me. Can any apple support provide a solution for this or atleast give us a hint whether this is a hardware or software problem?

I have the same issue with my iPhone4.

I've restaured without applications but the light of the camera is never turn off.

What is the solution to this issue?

Have same problem. Sometimes I dont know why and how the Camera Flash Light turns on and does not turn off.