The high-profile arrest of former Toyota Motor Corp. executive Julie Hamp last month over importing oxycodone might fuel prejudice in Japan against the narcotic painkillers and other strong pain-relieving drugs, experts fear.

Hamp, the automaker's first female managing officer, was released by police without charge July 8 after spending 20 days in detention. She was arrested June 18 on suspicion of violating Japan's drug laws after she reportedly had her father in the U.S. ship her 57 tablets of the powerful prescription drug hidden in jewelry boxes.

It is illegal to import oxycodone into Japan without a prescription and prior permission from Japan's health ministry.