BERLIN (AP) _ Autopsy workers at dozens of German hospitals have removed brain membranes from corpses and sold them to a drug company without getting the permission of relatives, authorities said Friday.

In most cases, the workers pocketed the $18 paid for each membrane, said Franz Muentefering, the health minister for North Rhine-Westphalia state. The membranes are used in medication to treat connective tissue defects.

The state's chief hospital regulator, Dr. Julius Siebertz, said workers at 90 hospitals across Germany were involved in selling the membranes to the Hesse state drug company, Braun-Melsungen.

Although not explicitly illegal, the practice is highly questionable because permission was not secured from relatives, Siebertz said.

In 18 cases his office investigated in North Rhine-Westphalia, relatives of the deceased ''were not appropriately informed'' about the removal and sale of the membranes, Siebertz said in a telephone interview from Duesseldorf. In most cases, hospital authorities were not informed either, he said.

In two cases, Braun-Melsungen had contracts with hospitals to buy the membranes, Muentefering said. But in most cases, autopsy workers were directly solicited by the company and would handle the sale without hospital approval.

Tens of thousands of brain membranes are sold annually by autopsy workers, Der Spiegel magazine said in an article in December.

Braun-Melsungen officials could not immediately be reached for comment on Friday, but the company told Der Spiegel it has been buying human brain membranes for 20 years.

German researchers came under heavy criticism in November when it was revealed they had used more than 200 human cadavers in automobile crash tests since 1975.