There were no signs of foul play in the death of a US Centers for Disease Control and Prevention epidemiologist who likely drowned, officials said Thursday.

The remains of Timothy Cunningham were discovered Tuesday in the Chattahoochee River in northwest Atlanta, police spokesman Carlos Campos said.
Cunningham, 35, was last seen on February 12.

The preliminary cause of death is drowning, Fulton County Chief Medical Examiner Dr. Jan Gorniak told reporters. The manner of death has not been determined, she said.

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

Police are awaiting a final report from the medical examiner, but unless new information comes forward, the investigation is expected to conclude soon, officials said.

Cunningham's family released a statement Thursday night saying, "We sincerely thank all of you for the support and kindness you have shown our family during this difficult time. We are processing this incomprehensible loss and request time and space to grieve."

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. The rumors were debunked by police and his family.