The 'Friends' star - who died aged 54 in October 2023, with multiple prescription medications found at the scene - is the subject of a shock report that says he lied about being sober before his death and had a history of being abusive to women.
One of the sources in the bombshell Us Weekly report told the publication: "(Matthew) would do the FaceTime thing and get to know them.
"Then it would be like, 'Let's hang out,' and he would say (to come to his house,)
"He wasn't out in public anymore. That's how he snuck things past people."
Among the other explosive new allegations that could tarnish Matthew's legacy are that he "threw a coffee table" at his ex-fiancée Molly Hurwitz in the years leading up to his death after she allegedly confronted him about cheating in 2021.
Despite the allegations Matthew was still using drugs when he died, his long-time friend and co-star Jennifer Aniston, 54, has said he was not "struggling" in the days before his passing.
The 'Morning Show' actress told Variety in December: "I was literally texting with him that morning, funny Matty. He was not in pain. He wasn't struggling. He was happy."
A woman named Athenna Crosby, who was seen dining with Matthew a day before he died, also repeatedly said he was in good spirits and claimed he had not relapsed.
The 25-year-old model told Fox News Digital in November: "He was 100 per cent sober when he passed.
"He was extremely positive, sober, acting normal, spoke very well, did not give me any impression that he was under drugs or alcohol of any kind."
No illegal substances were found at Matthew's $6 million mansion in the Pacific Palisades area of Los Angeles, where he was found dead in his hot tub.
But among the prescription drugs police found at the house were antidepressants and anti-anxiety medications.
Initial tests found Matthew did not have fentanyl or meth in his system when he died in his hot tub, and the final autopsy report attributed his cause of death to the "acute effects of ketamine" which can be used to treat depression.
Sources also told Us Weekly Matthew had been abusive towards women before his death, though none of the insiders of the alleged victims were named.