What we do know, however, is that the investigation has reached a sensitive stage.

The question remains how far, or rather, how high, the investigation will reach.

The investigation is now reaching what people involved in the case describe as an important turning point.

I want the investigation to go forth quickly and reach a conclusion.

But despite all the fear in the town, the news media attention and political pressures, the investigation reached a dead end in two months.

"Results will be reported as this investigation reaches its conclusion."

The Commission's investigations on this have not yet reached their conclusion.

May we know the stage this investigation has reached, and whether any measures have been taken?

The investigation into the reasons and consequences of this accident has reached a dead end at the moment.