"We found him through a very vigorous investigation."

But vigorous legal investigation of White House conduct during the 1996 election could change the legislative climate.

The department waited far too long to get a vigorous investigation under way.

He added that police ought to pursue a "vigorous" investigation to ascertain what had taken place.

But the call for a more vigorous investigation is also coming from other structural and fire experts.

He said a "vigorous investigation" on the case was continuing.

This question is under vigorous investigation; the answer to which could shape the future of cancer treatment.

Last week, the board demanded a vigorous investigation to identify the officers involved and seek their removal without pay.

In this case, you can expect a most vigorous investigation.

And at this moment, are there no murder cases that require vigorous investigation?