Don't look now, but President Reagan's campaign committee is using the Freedom of Information Act in all sorts of ways that President Reagan's Justice Department views with official disdain.

The case involves the Reagan-Bush Committee's efforts to block the Federal Election Commission from moving ahead with an audit that is expected to accuse the Reagan campaign of election law violations and call for repayment of nearly $1.6 million in federal funds.

The campaign committee, which filed for an injunction Aug. 10, prefaced its suit with a series of FOIA requests for auditors' work papers and other documents used in an interim FEC audit report recommending the big repayment.

The committee's attorneys then went into U.S. District Court here to complain that the FEC had failed to come up with the records within the deadlines provided by law. They maintained they needed the records to make a proper response to the findings. The commitee has also continued to make new FOIA requests while the lawsuit is pending.

According to the Reagan administration, that should not be permitted. In Senate testimony last week, the Justice Department assailed the use of FOIA to avoid rules of discovery and hamstring government agencies in administrative and legal proceedings.

Urging Congress to end the practice, Justice complained that "most government agencies report significant numbers of such requests, whose purpose is to avoid applicable rules of discovery and sometimes, where the government is a party, to harrass and burden government agencies."

Justice also contended that the existing exemptions under the law need to be broadened to protect "the operating rules, guidelines and manuals of procedure for government investigators or examiners," including auditors.

According to the FEC, the commission refused to provide the campaign with some documents because, for example, knowledge of the contents "would enable a committee to hide or obscure apparently improper contributions."

The Reagan campaign's lawyers replied that disclosure of such information was "essential to permit candidates and their committees to understand and comply with the law."

The FEC has also said virtually all of the documents sought by the Reagan-Bush committee have been "available to them for months, either on the public record or from the Audit Division" and that the commission has "substantially complied" with most of the committee's FOIA requests by now.