Can anyone shed a bit of light on this Diana inquest. I know she died about 10 years ago now and I know there has been an inquest started into her death but why? and who's paying for it exactly?

Up until now I havent really put to much thought into it because I really did not care but I got thinking about it last night. Why 10 years on are we now having an investigation into her death when the casue of death before was down to an RTA!. Who's decision would it be to call this inquest and who pays for it?