How to get rid of cache while loading an image?

hey folks,
does anyone know a good way of unloading content from loader object? I want to load a same image few times (backend overwrites old images with new ones) and all I get is bitmap data that is initialy being loaded the first time. So I guess bitmapData is stuck in cache by default and I cant get rid of it.
I tried following:
loader.unload()
loader.contentLoaderInfo.content.unload() before each load() call
setting loader object to null
setting urlRequest.useCache to false
naming loader instance to a unique string
naming loading content to a unique string.

Any ideas, PLEASE?