Atlanta (CNN) The CDC worker who was missing for nearly two months before his body was found in a river in Atlanta died of suicide by drowning, the Fulton County Chief Medical Examiner Dr. Jan Gorniak told CNN Wednesday.

Timothy Cunningham, 35, was last seen on February 12. His body was discovered in the Chattahoochee River in the northwestern part of the city on April 3.

In April, police said there were no indications of foul play in his death.

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Authorities made a positive ID of the remains by using dental records, Gorniak said last month.

Cunningham's disappearance prompted a high-profile police search and a $10,000 reward for clues. As days went on, internet rumors circulated that the case was tied to his alleged role as a flu vaccine whistle-blower at the Centers for Disease Control and Prevention. The rumors were debunked by police and his family.

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