这个which引导的定语从句中关系代词是作间接宾语吗？

UptoA$15bwouldbespenton environment protection，whichtheprimeministernotedsaysalotaboutwherethethreatsarecomingfrom.

期待老师解答，谢谢。

Up to A$15b would be spent on environment protection，which the prime minister noted says a lot about where the threats are coming from.
【翻译】高达150亿澳元将用于环境保护，总理指出，这“充分说明了威胁来自什么地方”。

这是一个“嵌入式定语从句”。其中，the prime minister noted 为“嵌入式”主句，which says a lot about where the threats are coming from 为其宾语从句。
which 作从句主语，指代前文整个主句内容。

say a lot about...充分说明。