Further investigation is clearly warranted.

进一步调查显然是必要的。

The case does not merit further investigation.

这个案子不值得进一步调查。

Further investigation was hindered by the loss of all documentation on the case.

由于有关此案的材料全部丢失，进一步的调查受到了阻碍。

The company confirmed the news and said further investigation was underway.

该公司证实了这一消息，并表示进一步调查正在进行中。

A few others look worthy of further investigation.

另一少部分貌似值得进一步研究。