LOS ANGELES (AP) _ The leading maker of silicone gel breast implants is being investigated by the Los Angeles prosecutor to find out if Dow Corning Wright Corp. marketed the devices without notifying the state of health risks.

Dow Corning Wright, notified Thursday of the probe, said it wasn't necessary and the Arlington, Tenn.-based company hired former U.S. Attorney General Griffin Bell to conduct a separate inquiry, company spokesman Robert Grupp said.

District Attorney Ira Reiner informed the company that a preliminary review of documents supplied to the Food and Drug Administration ''indicate that an investigation is warranted.''

The investigation is believed to be the first under the state's new Corporate Criminal Liability Act.

The law, effective this month, requires corporate managers to notify California regulatory agencies in writing about any ''serious concealed danger'' in their products.

Maximum penalty for breaking that law is three years in prison and a $1 million fine.

The FDA is also scrutinizing Dow Corning Wright for its role in disseminating safety information about silicone gel breast implants. In the meantime, the federal agency has declared a moratorium on the sale and use of the implants.

Dow Corning Wright is a subsidiary of Dow Corning Corp. of Midland, Mich.