Who was Ada working for in RE4

[Vogue_Dirge]

The actual entity isn't really known. It's just referred to as The Organization, or The Agency.

[Im_just_Paul]

Wasn't she working for someone else though?

[jimmyjoejangles]

she betrayed him for the love of leon, it was always for leon...

[Im_just_Paul]

This has always bothered me. Who did she betray Wesker for? Is this ever clearly answered in RE stories, or am I just overlooking something?