Investigative reporting, in case you hadn't noticed, is very much in vogue these days. Newspapers networks and local TV outlets have turned loose their ferrets, to sniff out the unmistakable stench of corruption in high places.

Alas, with Nixon basking in his Elba by the Pacific, corruption in high places has become much harder to find. Even Bert Lance-whatever he might have accomplished by gymnastic accounting-is a piker in the surreptitious banking business alongside Bebe Rebozo.

But te news business, like any other assembly line, has a product to put out. Unless he relishes covering fires or fashion shows, an investigative reporter had best turn up investigative stories with tim-card regularity.

Buried in government, industrial and academic documents lies a wealth of publicly available information that has never truly been made public. Some of the best investigative reporting has been done by such diligent researchers of this public record as I. F. Stone and Morton Mintz. Unfortunately, there are few practitioners of their craft.

What many newspapers and TV passoff as investigate reporting is something entirely different. Instead of indepth research, journalists are encouraged to spice their stories with allusions to "bootleg copes" of "confidential reports" from unnamed "sources." In some instances, the reporting actually entailed an investigation. All too often, however, there is less to such stories than meets the eye.

Every day on Capitol Hill, the press receives enough paper to housebreak a herd of elephants. Committee reports, press releases and documents of various sorts all vie for the journalist's attention. Most never make it past the trash can.

Add to that pile the paper disgorged by the federal bureaucracy, trade associations and assorted interest groups, and you've buried the elephants. Indeed, the best way to keep a secret in Washington may be to put it in a press release.

A small chunk of this mountain of paper finds its way into print or on the air. Editors naturally want more than routine material and exhort their charges to come up with exclusive stuff.

Enter now the intrepid investigative reporter hot on the trial of a bureaucrat or member of Congress with a story to tell. The latter knows that if he releases his report to the media in the normal manner-with an embargo date and time-it will probably be lost in the mountain of paper. He, too, would like exclusive treatment.

So, he leaks a copy of his report a few days ahead of the embargo. It's a perfect set-up for mutual back-scratching. The reporter gets his scoop and scores brownie points with his editor. The bureaucrat or congressman gets favorable publicity or revenge against a rival.

Although this type of reporting has been disparaged as "Xerox journalism," it has become a model in many newsrooms. It has also been honored by the elite of the news business. Several years ago, a Treasury employee leaked copies of departmental documents to a newspaper reporter. The resulting story was important but hardly excpetional. Nevertheless, the reporter won a Pulitzer Prize.

One cannot blame the reporter for writing the story; that, after all, is his job. One has to wonder, however, about the editors and publishers who believe such ordinary fare merits so extraordinary an award. By placing greter value on a leak than they do on the substance of a story, are they setting or do they merely reflect, the standards of today's newsrooms? Whatever the answer, those in the news business need to rethink and, one hopes, redefine their notions about investigative reporting.