宾语从句
sb.toldsb.sth.
he told us sth.主语是he谓语是told间接宾语 是us直接宾语是sth. 而现在sth是用整个句子that the case was being looked into来充当
又因为the case was being looked into 这案子已经在调查中, 这个句子是一个完整的句子了,所以当它作为宾语从句时,用that引导,that也可以省略掉