But the F.B.I. has called the tip that led agents to the site the most credible lead in years.

And it comes from a credible lead who came to our attention recently via a law enforcement colleague.

"The credible lead is somebody whose possible connection to the hijacker is strong," she says.

No credible leads were received.

Naw, but we've got a credible lead.

With his goofy Joe E. Brown smile and a singing voice that is too plain for the operetta, he does not make a very credible romantic lead.

But the Government remains prepared to follow any credible lead that may serve to resolve any unanswered questions in the case.

Even so, F.B.I. officials have called the information from Mr. Wells the most credible lead they have received in years.

We shall certainly follow up any credible leads given to us and report what we might find as well as any denial of access.

"We don't classify that as a credible lead," Chief Moose added.