Independent counsel Lawrence E. Walsh's criminal probe of the Iran- contra scandal has discarded several dozen arms-smuggling cases once touted as leads and now focuses on at least four inquiries into possible misdeeds by the Reagan Administration and private organizations, officials said Wednesday.
The White House end of the inquiry widened this month with a request by Walsh for documents from the offices of more than a dozen Administration officials previously not involved in the probe, one source said.
That document request was said to include some files from the office complex of former White House Chief of Staff Donald T. Regan, but primarily involved several National Security Council offices with potential links to the Iran arms deal or with aid to rebels in Nicaragua.
Three months into the inquiry, Walsh's office is continuing its wide-ranging investigation into the White House and CIA roles in the Iran affair. Separately, sources said, it is pursuing probes of:
--Miami-based Southern Air Transport, the cargo airline apparently used by former NSC aide Oliver L. North and associates to ship arms to Iran and to serve as a front for a variety of contra-related aid programs.
Besides Southern Air's links to North, Walsh is continuing an inquiry into the Justice Department's role in delaying an FBI investigation of the airline last autumn, shortly before the Iran dealings became public.
--Maule Air, a Georgia firm that last year sold short-takeoff-and-landing aircraft to a Panamanian dummy company apparently controlled by North and one associate, retired Air Force Maj. Gen. Richard V. Secord. The planes later were used in the rebel war in Nicaragua.
--Conservative political fund-raiser Carl (Spitz) Channell, whose private foundations were depicted in White House documents as financial conduits to Swiss bank accounts controlled by North.
The Southern Air Transport and Maule Air cases are among a number of Justice Department investigations turned over to Walsh after the independent counsel was named to head the Iran-contra inquiry last Dec. 20.
Reviews Another 52 Cases
In later weeks, officials said, Walsh was given jurisdiction over an additional 52 criminal investigations of arms smuggling and related activities, all alleged at one time or another to be linked to North or the Iran-contra affair. The last 15 cases were given to Walsh on Feb. 10.
Although one government official with knowledge of the cases acknowledged this week that "some might come close to the line," none has been found so far to significantly involve federal officials, and all 52 have been returned to the Justice Department.
Walsh can re-enter any of those cases if the evidence later warrants, one official said, but limits on the counsel's staff require lawyers and agents to concentrate on the investigation's main targets.
Some Administration officials admit privately that they are dismayed at the independent counsel's decision to turn back the cases, in part because Justice Department investigators now must pursue the cases to their limits or risk being accused of dropping matters prematurely for political reasons.
Calls Walsh Discerning
Walsh, on the other hand, "knows a dog when he sees one," one official said of the 52 arms-smuggling probes.
The general nature of Walsh's inquiry into White House complicity in the scandal has long been clear. But, beyond allegations that North or others may have obstructed justice by destroying and altering documents related to the Iran and contra dealings, most specific areas of investigation remain secret.
A massive request for White House and NSC documents submitted by the independent counsel earlier this month implies that Walsh is casting a much wider net now in search of new evidence in the scandal, one Administration official said Wednesday.
The White House publicly described Walsh's request as a routine written list of records that the counsel's office had orally sought in recent weeks. Two officials close to the inquiry disputed that description this week, calling the new document request a significant expansion of the investigation.
Officials Respond to Requests
Nearly a dozen White House officials have been detailed almost full time to meeting requests from Walsh and the two congressional select committees examining the Iran affair, one official said.
One source said that either Walsh or the committees now have been supplied with virtually all known "relevant" documents in the possession of President Reagan, former National Security Advisers John M. Poindexter and Robert C. McFarlane, North and employees in the NSC political-military affairs division where North once worked.
The latest document request includes some papers from Regan's suite of offices. But it centers on NSC divisions whose files have yet to be fully scanned for evidence, including the agency's Latin American, Near East and Asian affairs and intelligence offices.
All three divisions normally would have been consulted on the Iran arms sales or secret aid to the contras, but they were said to have been bypassed by North, Poindexter and McFarlane to preserve secrecy.
Gets New Batch of Messages
A new batch of electronic messages from and among those offices also is being retrieved from NSC files and dispatched to Walsh. Similar messages already have been supplied to Walsh from the NSC political-military affairs office and from Poindexter and McFarlane's office or home computers.
The messages supplied so far include all existing computer "mail" on Iran and the contras sent or received by those NSC officials, dating to the day the officials were employed by the White House.
Missing, however, is a potentially significant number of messages that were electronically destroyed--deleted from computer memories by the push of a button--before the weekly recording of NSC data on a permanent storage disk.