An Illinois pediatrician who took his own life penned a suicide note stating that he regretted falsifying vaccination records for children in his practice, according to several media reports.

Van Koinis, MD, age 58, who ran a practice in Evergreen Park, Illinois, was found dead from a self-inflicted gunshot wound in September, but officials just this week released the information about the suicide note.

Koinis was a known advocate of homeopathic medicine, and investigators think parents may have sought him out specifically to get false documentation showing their children had been immunized against communicable diseases when they had not, the Chicago Tribune reports.

"He was well known for being someone who was into homeopathic medicine, and from what we have determined, it was well known that people opposed to vaccination could go to him," Cook County Sheriff Tom Dart told the newspaper.

Dart said no evidence has been found to indicate that Koinis disregarded parents' wishes for their children to be vaccinated, but former patients of his should be checked to ensure that they received the proper immunizations. Koinis had been licensed to practice in Illinois since 1991, according to state records cited by the Tribune.

While it's unclear how many children may have been impacted, the note Koinis left suggested that he either doctored records or gave fake vaccinations over a period of 10 years.

"The length of time he mentioned and the fact that he was so focused on this as a regret of something he did, and the fact he committed suicide, led us to believe it was quite serious on many levels," Dart told the Tribune.

"The substance of the note he left was very broad and very specific about vaccination issues and records being faked. He was incredibly regretful for what he did and it was the only thing he mentioned in the suicide note," Dart added in an interview with WBBM-TV CBS 2 Chicago.

Dart told the station no one has been charged in connection with the pediatrician's suspected conspiracy to fake vaccination records, but that an active investigation was underway to determine whether anyone else may have been involved.

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