The ABC Action News I-Team is investigating the refurbished mattress industry, which experts believe may account for as much as 10 percent of all mattress sales.
These mattresses are made from parts of used mattresses, which are recovered, then sold in discount stores.
The people who make them claim they are "sanitized," but we found out, that might not always be happening.
During multiple days of surveillance at a Tampa refurbishing plant, we saw a constant flow of used mattress sellers coming to sell old mattresses to the company.
We followed one of the sellers as he trolled apartment complexes looking for more mattresses.
Our camera was there as he pulled a box spring set out of a junk pile and threw it into his truck to sell.
Most of these used mattresses sell for about $5.
We bought a refurbished mattress from a discount furniture store and asked forensic scientist Anna Cox to take it apart to see what was inside.
She used exam gloves, a microscope, a black light and a surgical scalpel in the process.
"Ok. You can see it here already. You can see it visually," Cox said, pulling away the new outer cover.
As it was removed, she discovered "not so new" parts of old mattresses.
"You can see visually, from just removing this, how dirty this mattress is," Cox said.
"These appear to be different mattresses that are just patched together and you really don't know the history," she said.
The surfaces of old mattress covers, which are used as part of the batting for the refurbished mattresses, are filled with yellow stains.
"Could be sweat. Could be the excessive amount of skin cells," Cox said.
She takes a photo of something shiny that looks like a bug.
"That looks like a hair," she said, pointing out another piece of debris embedded in the old mattress cover.
Then she pulled out the black light, which she uses as a crime scene investigator to identify body fluids like urine, semen and sweat.
"Holy cow. That is super bright!" Cox exclaims, as stains on the surface glow brightly.
"It's very, very bright right here. Very bright," Cox said.
"This would not live up to my expectation of something being sanitized," Cox said.
Coming up Thursday night, we'll look at what regulations exist for refurbished mattresses and why they're not always enforced.