Police were trying Tuesday to determine if mummified remains found in the home of a known hoarder in St. Louis, Mo., are those of the homeowner's mother who has not been seen in almost 20 years.

Gladys Bergmeier, 75, was known to be a pack rat whose house was filled with newspapers, plastic bags and trash. She died on Feb. 7.

This week, when relatives were cleaning out her home, family members found the mummified remains of an elderly woman, The St. Louis Post-Dispatch reported.

The body is presumed to be Bergmeier's mother, Gladys Stansbury, who moved into her daughter's home in 1993. Neighbors do not recall seeing her once in the time since.

The remains were dressed in a pajama top and camisole, with one sock on the right foot, and were wrapped in a plastic, multicolored curtain.

There were no signs of trauma on the body.

"[She] always had excuses as to where [her mother] might be. As time went on, people just stopped asking," a neighbor told the Post-Dispatch.

Dr. Julie Pike, a psychologist at Anxiety Disorders Treatment Center in Durham, N.C., estimates there are about 2 million people in the U.S. who have a hoarding problem.

"It’s a debilitating condition where they accumulate clutter to the point of impairment," Pike said.

For some people, the clutter becomes so bad, they cannot even leave their own home. When there isn’t any more room to hoard in the house, hoarders may spread their collection to the yard, garage and sometimes to their vehicles.

Some people don’t hoard material possessions; instead they hoard animals, which can create unsanitary living conditions. The Humane Society of the United States estimates 250,000 animals suffer from animal hoarding each year, and the Cummings School of Medicine at Tufts University has reported incidences of as many as 1,000 animals living in single-family homes.

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NewsCore contributed to this article.