If you were able to write to the directory you should have read/write priveledges. Have you rooted the device? If so something like Root Explorer or another file manager like ES File explorer should be able to deal with it.
Yes, this was purchased new, never rooted. What happened was I was dragging file from one directory to another and it dropped in wrong folder. I can copy it into another folder but if I select file, click delete and then confim I want to delete I get message cannot delete file.
Its very bizzare.... both the /data folder and the file when view properties say readable and writeable...... but no mater what I try cannot delete the file. I can play the file (its a video). Would not be over concerned if was not a 700M file so big waste of space.
Guess may need to back everything up the do factory reset.