Police officers in Pennsylvania are investigating the recent death of 20-year-old Claudia Adusei, of London, who died in a hospital after receiving an illegal silicone injection in the U.S., reports the BBC.

Detectives believe that the woman made arrangements online to have silicone injected into her buttocks, and that she flew to the U.S. specifically to receive the treatment. The illegal procedure took place at a hotel near the Philadelphia International Airport. She died the day after the incident.

Police searched the home of a woman who they believe helped set up the appointment, though no arrests have been made in the case. Detectives are pursuing a second woman whom they believe gave Adusei the injection.

The use of liquid injectable silicone is currently only used in legitimately approved clinical trials, according to the American Society for Aesthetic Plastic Surgery. Liquid silicone injections cannot be altered or removed, and there have been many reports published detailing severe complications from the use of the substance.

The Physicians Coalition for Injectable Safety advises those considering undergoing a cosmetic procedure that involves injections to plan their treatments carefully and to be sure that a qualified medical professional is conducting the procedure in an accredited facility.