A missing man was discovered dead in a Planet Fitness tanning bed Monday three days after he walked into one of the gym’s in Indianapolis, authorities and loved ones said.

The body of Derek Sink, 39, was found around 9 a.m. – about four hours after the fitness center opened its doors for business, according to reports.

The day before, Sink was reported missing by family who had not heard from him since Friday, the Indianapolis Star reported, citing police records.

A woman who visited the gym Monday morning told WTHR a foul smell was emanating through the building before the body was found in the tanning bed.

“The tanning bed has a door, I believe, but still, why are we not concerned that the tanning bed has been closed for three days, potentially?” Elizabeth Len said.

The gym closes at 9 p.m. on Fridays and is open from 7 a.m. to 7 p.m. on Saturdays and Sundays, according to its website.  

Sink’s family told the local station that their loved one had dealt with drug problems and a needle was in the room at the Planet Fitness.

An ankle monitor worn by Sink helped authorities pinpoint where he’d been, an aunt reportedly said.

His relatives remembered him as a loving person.

“We were deeply saddened by the passing of one of our members, and the franchise owner is working with the local authorities in their investigation,” a Planet Fitness representative said in a statement to the outlet.

“At Planet Fitness, we have robust operational brand protocols in place, as the safety and well-being of our members is our top priority. We are working closely with our local franchisee to ensure they are upholding those brand protocols.”

A cause and manner of death has not been determined so far, but foul play is not suspected.