Edwin Meese III, President Reagan's counselor, is the aide who triggered the Justice Department investigation of White House national security adviser Richard V. Allen, according to a White House statement yesterday.

Meese also checked with the FBI on the status of the probe at a key moment in the feuding between Allen and Secretary of State Alexander M. Haig Jr.

It also was learned that the Justice Department yesterday ordered FBI agents back into the field to reopen their investigation of the $1,000 in cash that Allen says he received from Japanese journalists who intended it as a thank-you gift to Nancy Reagan, who had granted them an interview.

Allen helped arrange the interview as one of his many contacts with a group of Japanese with whom he had dealings as a consultant before entering government. Since becoming Reagan's national security adviser, Allen has continued to meet with and advise on an ad hoc basis some of the clients of his former consulting firm, Potomac International Corp., according to a number of sources in Japanese-American consulting and diplomatic circles.

White House communication director David Gergen insisted that Meese's action in checking the status of the Allen investigation did not violate the White House policy which states that contacts between the White House and the Justice Department should be through Fred Fielding, counsel to the president.

"As we have said before, it's our view that this matter has been and continues to be handled by White House authorities in an appropriate and proper manner," Gergen said, reading from the statement.

Gergen and other White House officials maintain in general that they should not comment on the matter while the Justice Department is investigating. They have issued a series of explanatory statements since the incident became known last Friday, however, either to correct their misstatements or to put their interpretation on a newly disclosed event.

Meese first notified the Justice Department of the cash shortly after it was discovered in September and followed up in a Nov. 6 conversation with an FBI official Gergen declined to name. Other sources said Meese had talked to FBI Director William H. Webster.

A day earlier, Reagan had summoned Allen and Haig to the Oval Office to order an end to the bickering which had led Haig to charge that someone in the White House was waging a "guerrilla campaign" against him.

Meese checked with the FBI the next day "to determine whether any administrative action was necessary" against Allen, according to the statement. Meese decided that no disciplinary steps were needed and so informed the president, Gergen said.

At the Justice department, a spokesman said the preliminary investigation of Allen is not complete and that when it is finished it must be reviewed by deputy attorney general Edward C. Schmults and then by Attorney General William French Smith. Reliable sources said the FBI had not been conducting interviews for at least a week, but that agents were asked to do additional interviewing even though department attorneys recommended closing the case without a court-appointed special prosecutor.

Allen's meetings with former clients since taking office do not violate any law and are often difficult to distinguish from the normal contacts in his official capacity with foreign dignitaries and corporate leaders. But for Allen, whose commercial background sets him apart from many of his predecessors in the national security adviser's post, these encounters have posed special problems.

Allen acknowledged Wednesday that he has had as many as four meetings this year in the White House with one of the chief Japanese business contacts of his former private consulting firm, Tamotsu Takase, the man whose wife helped the Japanese magazine Shufu no Tomo get an interview on Jan. 21 with Nancy Reagan.

In one of the Takase meetings, on March 23, Takase escorted the No. 2 executive of Japan's Toyota manufacturing empire to the White House to confer with Allen on, among other things, the trade attitudes of the Reagan administration. Before joining the administration, Allen served as a paid consultant to a Japanese parts manufacturing company, Aisin Seiki Co. Ltd., associated with the Toyota group and headed by a member of the Toyoda family, according to knowledgeable sources.

Allen said Wednesday that the March 23 session was the only meeting this year between him and a Japanese auto executive. But Allen has met several times with Yasuhiko Suzuki, the Washington vice president for Nissan U.S.A., the Datsun marketing company that kept Allen on a $100,000 annual retainer until October, 1980, according to sources who observed the meetings. Suzuki acknowledged meeting at least twice with Allen this year.

Toyota officials were unable to say Wednesday whether Allen, Takase and Toyoda discussed auto issues during the March 23 meeting. But, The Washington Post has learned that subsequent to the White House meeting, Takase returned to Japan and briefed corporate leaders on the Allen meeting. Takase said he had received Allen's frank analysis of trade attitudes that would affect the Japanese automobile industry.

"On auto exports," Takase told the Hudson Institute's Asia Pacific Conference in Karuizawa, Japan, during April 14 to 17, Allen had said there was a problem with communications. In his talk with Allen, Takase told the group, the national security adviser said that the key people in the White House were committed to free trade concepts, but that their position was complicated by a growing protectionist movement in Congress.

Takase, according to the notes of his talk taken by a member of the audience and made available to The Washington Post, said that Japan would be "handicapped" without a better analysis of what Ronald Reagan was doing.

Sources in the international consulting community said in interviews earlier this year that Takase was billing himself as a consultant who could provide a good analysis of the Reagan administration by virtue of his close relationship to Allen.

Prior to Jan. 20, Allen and Takase both served as consultants to a Japanese trade and research organization, Technova Inc., whose board of directors is comprised of generally conservative executives from a cross-section of Japanese industrial interests and whose chairman is Minoru Toyoda. After Allen sold Potomac on Jan. 18 to former Reagan aide and speechwriter Peter D. Hannaford, Technova engaged Hannaford to conduct a joint study with a University of Michigan professor on Japanese and American automobile issues.

The study is being jointly underwritten by Japanese and American auto giants, including General Motors, Ford Motor Co. Nissan Motor Co. (Datsun) and Toyota Motor Co. Among those serving on the policy board are both Shoichiro Toyoda and Takase.

During sensitive White House discusssions on limiting Japanese auto imports, Allen told senior presidential aides and others who participated in the decision making that he would remove himself from the process because of his former work for Datsun's American subsidiary.

But his meeting with Toyoda and Takase and the subsequent report Takase gave in Japan indicate Allen's interest in keeping his former clients and Japanese associates apprised of the mood and tenor of the White House policy-making apparatus.

A few weeks before the Japanese announced--with specific urging from the White House--voluntary limits on auto imports, Allen was Suzuki's guest at the April 22 convention of the Automobile Importers of America, a trade organization that represents the interests of foreign auto makers. Allen has also lunched with Suzuki on at least three other occasions, according to a source who observed the meetings.

Allen has maintained an especially close relationship with Hannaford, who along with presidential assistant Michael K. Deaver handled most of Ronald Reagan's private business affairs from 1974 until he announced for the presidency. Hannaford said earlier this year in an interview that he continued to discuss the firm's clients with Allen after Allen joined the administration. Hannaford said these discussions were chiefly concerned the proper "protocols" with which Allen's former clients were to be treated.

Hannaford has also said that he dines occasionaly with Allen and sees him at social functions connected with the Reagan administration.

One Republican source in the international consulting business said that Allen and Hannaford have met together with at least one foreign diplomat since Jan. 20 to introduce Hannaford as a "contact" man to the administration.

Staff writer Charles R. Babcock contributed to this report.