A criminal probe into Matthew Perry's death may include information from Charlie Sheen's ex-wife, Brooke Mueller.

Mueller, 46, has reportedly been questioned "multiple" times about Perry's October death, sources told InTouch Weekly.

Authorities reportedly attempted to contact Mueller at the sober living house where she's staying, but the actress wasn't home when officers arrived with a search warrant last month.

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Matthew Perry wears blue sweater next to Brooke Mueller in a sheer dress.

Brooke Mueller may be connected to Matthew Perry's death investigation. (Getty Images)

A source told the outlet that Mueller was "out exercising" at the time but was "completely cooperative" when she returned.

"She’s hired lawyers and has had multiple meetings with law enforcement since they arrived at her sober living house with a search warrant. She’s being tight-lipped about the situation," the insider said.

"It’s tough to say or know exactly what her role is [in Matthew’s death], but she’s adamant she had nothing to do with that."

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Mueller's representatives did not immediately respond to Fox News Digital's request for comment.

Brooke Mueller and Charlie Sheen photographed before their divorce

Charlie Sheen and Brooke Mueller were married for three years and have twin boys. (Getty Images)

Authorities reportedly seized an iPhone and a laptop from Mueller. Their relationship is still undetermined, but a source shared that Mueller met the late "Friends" star "in rehab," where they "formed an unexpected friendship."

Mueller and Sheen were married for three years before divorcing in 2011. A judge recently granted Sheen full custody of their twin sons if Mueller failed a drug or alcohol test. The two share joint custody, although the twins primarily live with Sheen. 

Los Angeles Police Department officials confirmed to Fox News Digital the department is still actively working on the criminal investigation into Perry's death. 

Friends star Matthew Perry portrait

Matthew Perry died in October due to the "acute effects of ketamine," the County of Los Angeles Department of Medical Examiner said. (Getty Images)

"The department has an open and ongoing investigation into Matthew Perry‘s death," authorities said.  

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The "Fools Rush In" actor died Oct. 28 after an apparent drowning in a hot tub at his home in the Pacific Palisades area of Los Angeles. He was 54. 

Last month, Los Angeles Police Capt. Scot Williams said in an email the department was working with the DEA and U.S. Postal Inspection Service to determine why Perry had so much ketamine in his system when he died in October, The Associated Press reported.

When Fox News Digital asked about the status of the investigation, the U.S. Attorney's Office declined to comment.

Friends stars cuddle in bed for sitcom promo photos

Matthew Perry starred alongside Lisa Kudrow, Jennifer Aniston, Courteney Cox, Matt LeBlanc and David Schwimmer in "Friends." (Hulton Archive)

Trace amounts of ketamine were detected in Perry's stomach contents, according to his autopsy, which listed his death due to the "acute effects of ketamine."

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"The exact method of intake in Mr. Perry's case is unknown," the report stated. Other conditions that contributed to his death included "coronary artery disease, buprenorphine effects," the report said. "Prescription medications and loose pills" were also found at his home, according to the autopsy.

Ketamine is a dissociative anesthetic drug with "established medical and surgical uses," the autopsy detailed. Perry reportedly received "ketamine infusion therapy for depression and anxiety."

Matthew Perry wears denim shirt and vest in portrait photo

Matthew Perry was 24 years old when he began portraying Chandler Bing. (Reisig & Taylor/NBCU Photo Bank/NBCUniversal)

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His last known treatment was more than one week prior to his death, but the medical examiner determined "the ketamine in his system at death could not be from that infusion therapy, since ketamine’s half-life is 3 to 4 hours, or less."