Investigators for Congress and the Treasury Department are closing in on the U.S. Customs Service, and the day of reckoning is coming for Customs employees who have been dodging charges of internal corruption.

We have been tracking the investigations being done by a House subcommittee and the Treasury Department inspector general for months. They are looking into charges that the Customs internal affairs department, which is supposed to police corruption in the agency, doesn't when friends are involved. Last February we reported that Customs employees across Texas had turned over thousands of pages of documents to the internal affairs department. Those documents listed alarming allegations from misuse of funds to outright fraternization between Customs agents and drug dealers in the Southwest.And these are the people at the front line of defense in the war on drugs. Many of those named in the documents held management positions. Internal affairs pulled its punches and the whistleblowers were harassed. One management official whose name turned up in the whistleblowers' documents had already been investigated three times at his previous Customs post. Each time the charges were substantiated. Twice, as "punishment" he has been transferred to new jobs that amounted to lateral moves.

Rep. Doug Barnard, D-Ga., chairman of the House subcommittee that oversees Customs, didn't pull his punches when he sent a letter of warning recently to Customs Commissioner Carol Hallett. He cited a sworn affidavit from a Texas Customs agent who was told by his supervisor, "As long as the commissioner does not know that internal affairs is corrupt, she will continue to use them . . . since she has no choice in the matter. . . . They are all she has to rely on to conduct her investigation." Hallett has been on the job for almost two years. Several Customs employees told our associate Dean Boyd that they think Hallett wants to get to the bottom of the mess, but they suspect she is being shielded from the worst of it by some of her subordinates.

But with Congress and the Treasury Department now doing independent investigations, some in Customs are beginning to sweat because they can't pull the strings anymore. One employee told us, "Most of these guys have worked in the internal affairs network and they all know each other. . . . But today all that has changed. They're not in the loop and they're scared."

In 1989 the General Accounting Office issued a report saying if someone was to make a claim about corruption in Customs, there was no guarantee the claims "would receive proper consideration."

The report included one of the most unsettling examples of internal affairs agents in action. In July 1987, internal affairs was told that someone from Customs may have broken into the GAO offices and stolen files while the GAO was investigating Customs. Internal affairs did not investigate. Months later an anonymous tipster called the Treasury Department and repeated the claim. Treasury verified that it had indeed happened, but the burglars, who turned out to be internal affairs agents, were given a slap on the wrist.

There is a good chance the latest probes will show nothing much has changed.