PHOENIX – An Arizona man says a body donation center where FBI agents reported finding buckets of human organs and a Frankenstein-like body sold his mother’s body to the U.S. Army for “blast testing.”

Jim Stauffer told KNXV he contacted the Biological Resource Center after his 73-year-old mother, who had Alzheimer’s, died five years ago. He said he now feels “foolish” because he only contacted the donation facility after his mother’s neurologist couldn’t accept the body at the time.

Stauffer said he signed BRC paperwork outlining what he would and would not permit the center to do with his mother’s body, and, several days later, received a box with a majority of her ashes.

He had no idea what actually happened until he says Reuters combed through internal BRC documents obtained by authorities and found out Stauffer’s mother, Doris, was sold to the military for “blast testing.”

“She was then supposedly strapped in a chair on some sort of apparatus, and a detonation took place underneath her to basically kind of get an idea of what the human body goes through when a vehicle is hit by an IED,” Stauffer said.

Stauffer, who has joined a lawsuit against BRC and Stephen Gore, the company’s owner, said he remembers the mention of explosives on the paperwork he signed years earlier and didn’t give his consent.

“Every time there’s a memory, every time there’s a photograph you look at, there’s this ugly thing that happened just right there staring right at you,” Stauffer said.

When federal authorities raided the Arizona facility of the BRC in January 2014, they made a horrific discovery: bodies piled atop one another, buckets full of body parts and other unsettling scenes, details that came to light recently when a former FBI agent gave a statement for a lawsuit.

Thirty-five relatives of people whose bodies were supposed to be donated for science research between 2010 and 2014 have sued officials who worked at BRC in Maricopa County or its facility in Illinois.

The grim discoveries were detailed in a civil lawsuit which was first filed in 2015, has been amended several times and is headed for trial this fall in a Phoenix court. It alleges officials deceived relatives who donated the remains of their loved ones and the company conspired to traffic bodies and body parts for profit.

CNN Wire contributed to this report.