IONIA, Mich. (WOOD) — An Ionia therapist has been accused of criminal sexual conduct after he had an affair with a patient.

According to court documents, Derek Robertson faces one count of fourth-degree criminal sexual conduct, three counts of health care fraud, and three counts of delivery/manufacture of a controlled substance.

Robertson, a former social worker based at Viewpointe Counseling in Ionia, had a sexual relationship for nearly a year and a half with a woman who was seeing him for treatment of post-traumatic stress disorder, according to state investigators.

Investigators said Robertson admitted to having sex with his patient in his office and at his home.

From June 2021 to June 2022, the woman told investigators they had sex during appointments twice a week. The state says Robertson admitted that he continued to bill her for therapy even when they only had sex during appointments.

In therapy, she told Robertson she was sexually assaulted in 2019. Investigators said Robertson insisted on having sex with her in a similar environment to where the assault happened, which was a traumatic trigger for her.

Robertson’s license was suspended on April 10 by the Michigan Department of Licensing and Regulatory Affairs.

In late March, Viewpointe Counseling posted on Facebook confirming Robertson was no longer working in the building.