A spa owner from South Texas, US, has been sentenced to three years in prison for illegally injecting liquid silicone into clients at her salon – a practice that led to the death of one woman in 2013.

Federal prosecutors found that 38-year-old Elva Navarro of Hidalgo injected at least 30 women and falsely told them she was trained and certified to provide the injections – claiming that the silicon was Botox. The use of liquid silicone is not approved by the US Food and Drug Administration.

While one woman died, another client spent 17 days at a hospital recovering from damage caused by the injections that cost her US$750 (€635, £496), according to local media reports. The hospitalised victim had to undergo several corrective surgeries as a result of the liquid silicone ‘treatments’.

Navarro pled guilty in June to one count of receiving an adulterated device through interstate commerce with the intent to defraud or deceive.

Highlighting the importance of checking aesthetician’s credentials, the spa owner has a rich criminal history. In November 2013, Navarro was arrested for practising medicine without a license, and in 2012, she was arrested for allegedly kidnapping a student and holding her to ransom.