Despite testing for mold several months before their deaths, actress Brittany Murphy and her husband Simon Monjack may have died from pneumonia brought on by consistent exposure to mold, Murphy's mother alleges in a lawsuit filed this month.

Murphy, who starred in such films as "8 Mile" and "Girl, Interrupted", died unexpectedly December 20, 2009, while Monjack died in May 2010. The Los Angeles County Coroner's office originally ruled the primary cause of both deaths to be pneumonia, and it did not find any evidence of mold exposure.

Still, assistant chief coroner Ed Winter requested that the home be inspected for mold. According to The Hollywood Reporter, Murphy's mother Sharon initially refused the inspection, finding the mold theory to be implausible. Monjack previously conducted an inspection for mold, but none was found.

"Due to the inferior products used by the builder and subcontractors, the Murphy home had a persistent leak problem," Murphy family spokesman Roger Neal told People Magazine. "In October 2009, to insure the home was safe to occupy, the [Monjack's] attorney hired a well-respected company to conduct a full inspection of the home, which would include … checking for any possible mold."

Sharon Murphy has since tried to sell the home, and the results of a routine home inspection led her to believe that mold may have contributed to the deaths of her daughter and son-in-law. She is suing the attorneys who represented her in a suit against the home's builders, alleging that she was not advised she could file a wrongful death lawsuit due to the presence of mold in the home.

While exposure to many types of mold is harmless, some strains, such as the "black mold" (S. chlorohalonata) believed to be found in the Murphy home, can be toxic. Poor indoor air quality brought on by mold growth can cause negative health effects, so homeowners should regularly work with a home mold inspection service to ensure their families remain healthy.