Lallas said the Los Angeles Police Department began investigating possible elder abuse of Lee in February and that Lee had signed a declaration expressing "concerns regarding the intention and conduct of various people."
Morgan, a memorabilia collector, inserted himself in Lee's life as his caregiver after Lee's wife Joan died in July, according to a statement of facts filed with the request for the restraining order. The documents claim that Morgan allegedly isolated Lee from his family and that last week he moved Lee from his longtime home into a condominium.
Morgan "took control of Mr. Lee's home on February 15, 2018. He hired a security team and made household decisions," according to the court documents obtained by ABC News.
Soon after, Lallas was fired by Lee and he was unable to get in touch with Lee for an explanation on why he was dismissed, according to the court papers.
Morgan made a financial elder abuse report against Lee's former business partner in December 2017, the documents show.
"Since then, Mr. Morgan has instructed security to deny family members and others who have helped Mr. Lee in the past access to Mr. Lee. Family members have been unable to contact Mr. Lee by telephone," the court papers say.
Lallas said LAPD investigators "determined that in order to protect Mr. Lee, it was necessary to obtain an emergency protective order and, thereafter, an elder abuse restraining order against Keya Morgan."
"Mr. Lee has a large estate worth over $50 million and therefore is vulnerable to financial predators," according to the court documents filed by Lallas.
Morgan was arrested on Monday on suspicion of filing a false police report of an emergency after he was barred from entering Lee's home on May 30, while detectives and a social worker were conducting a welfare check, according to court documents. Morgan had called 911 to allegedly make a bogus report that burglars were in his home.
"Mr. Morgan's behavior, including, but not limited to, isolation and undue influence, places Mr. Lee's well-being at risk. He has been denied contact with his family members and other individuals that he has known and trusted for years," according to the court documents supporting the restraining order.
Efforts by ABC News to reach Morgan were unsuccessful.
Morgan told TMZ that he had cared for Lee "for the past many years, and have never had a problem directly with Stan."
Disney is the parent company of Marvel Entertainment and ABC News.