In the excitement that has surrounded the trial of Dr. Kenneth Edelin, a Harvard-related case that keyed prosecutors to the Boston City Hospital obstetrician has been ignored.

The Suffolk County district attorney's investigation at City Hospital that ultimately produced Edelin's indictment began in mid-1973 shortly after researchers from BCH published a study using fetal experimentation in the June 1973 New England Journal of Medicine.

Those researchers--including Dr. Leonard D. Berman, assistant professor of Pathology at Harvard Medical School, and Dr. Leon D. Sabath '57, then assistant professor of Medicine--were indicted the same day as Edelin last April for illegal removal of human tissue.

Newman A. Flanagan, assistant district attorney in Suffolk County, insists that as soon as he finishes with the Edelin trial he will proceed against the experimenters.

But other sources say that Flanagan's strongest case is against Edelin, and if he fails to obtain a conviction there he will abandon his charge against the researchers.