An investigation is underway to determine the causes of death of a man whose body was found in a tanning bed three days after entering a Planet Fitness in Indianapolis.

Monday shortly before 8:30 a.m., Indianapolis Metropolitan Police Department received a report of a body found at Planet Fitness.

The Marion County Coroner’s Office identified the man as 39-year-old Derek E. Sink.

According to police records obtained by 13News, Sink’s family last had contact with him on Friday and reported him missing on Sunday.

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A man was found dead at a Planet Fitness in Indianapolis. (Michael Nagle/Bloomberg via Getty Images / Getty Images)

Police could only confirm to Fox News Digital that they were investigating a death at the gym and did not provide details about the investigation.

A woman who was at Planet Fitness Monday morning told 13News she and other members noticed a foul odor in the building that got worse near the tanning rooms.

The woman also wondered how such a thing could happen.

“The tanning bed has a door, I believe, but still, why aren’t we worried about the tanning bed being closed for three days, potentially?” » asked Elizabeth Len.

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The body of a 39-year-old man was found in a tanning booth at an Indiana Planet Fitness, according to multiple reports. (Raymond Boyd/Getty Images/Getty Images)

Sink’s family told 13News he struggled with drugs and a needle was reportedly found in the room with him, while his aunt told the news channel he wore an ankle monitor that helped investigators determine he never left the gym.

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The family of a man found dead days after his death at a Planet Fitness in Indianapolis has called on the company to adopt stricter policies with an end-of-day checklist. (Don Emmert/AFP via Getty Images / Getty Images)

Planet Fitness released a statement to Fox News Digital confirming the death and shared its condolences.

“We were deeply saddened by the death of one of our members and the franchise owner is working with local authorities in their investigation. At Planet Fitness, we have strong brand operational protocols in place because safety and the well-being of our “Members are our top priority. We work closely with our local franchisee to ensure they are following these brand protocols,” McCall Gosselin, director of corporate affairs for Planet Fitness, said in a statement.

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Sink’s family also told 13News they hope to see stricter cleaning policies and an end-of-day checklist from staff to prevent this from happening to another family.

The circumstances of Sink’s death remain under investigation.