So, look for process with PID 10044
That would be the process which has a file open. The file was deleted some time ago, but the process is still running, and the file still exists on disk, and it is still growing. Only thing is, the file doesn't have a name anymore, but it is still using ever more disk blocks.
When you stop that process, the file will be deleted for real, and the diskspace will be recovered.
HTH,
p5wizard