A D.C. policewoman whose narcotic investigation led to the search of a high-ranking Drug Enforcement Administration secretary's home is now under investigation herself for possible misconduct in preparing a warrant for that search.

The secretary, meanwhile, has returned to work at DEA headquarters where she was one of three secretaries assigned to DEA administrator Peter B. Bensinger before the search. No criminal charges will be placed against her, officials said, because of the search warrant irregularity.

The unusual turnabout stems from the late May search of the home of Joan S. Jackson, 37, of 1213 Talbert St. SE. During the search, a gun and small amount of marijuana were found in the home and arrest warrants issued for Jackson and her husband.

Jackson informed her superiors of the results of the search after returning May 31 from vacation and finding the search warrant tacked to her front door. She was placed on leave pending an internal DEA investigation.

The DEA investigation is not yet complete, but Jackson was allowed to return to another job at the agency after the pending criminal charges against here were abandoned.

The search was based on an affidavit signed by police officer Sandra J. Austin, who reportedly has been told by superiors that she is under investigation for alleged misstatements in the affidavit.

The affidavit alleged that a police department source had recently purchased cocaine from a person known only as "Meathead" inside the Talbert Street home. No cocaine was found on the premises during the search, but officers reported they did find, among other items, a plastic bag with green weed and several partially smoked marijuana cigarettes.

Austin reportedly has told prosectors who are investigating her that the warrant was one of three typed by her and other officers at the 7th Police District on the same day. She said she did not type the one she signed and that any alleged irregularities in it should be attributed to the person who actually typed it, sources said. She contended further, sources said, that any irregularity in the warrant amounted only to a technical mmistake.

Austin's police powers were revoked June 19 and she has been assigned to desk work pending the outcome of the investigation by 7th District officers.

The arrest warrants against Jackson and her husband were dismissed June 20 by the U.S. attorney's office after a preliminary investigation.