Once we have made an investigation I'm sure that all will be well.

Sitting on the bed, he said that they'd been making investigations into my private life.

They say this made possible the major corruption investigations of the 1990's.

Yes, I understand all that, but will you make an investigation now?

"I am making an investigation into the circumstance of the murder."

I'd like to make a complete investigation of what happened.

Hence, they determined to make a complete investigation of the problem.

I know who he is now because I made a small investigation.

I am keen to go back and make a thorough investigation.

But they seemed to be making a very halfhearted investigation.