Charlotte Stewart has a theory of what could have caused the sudden death of her drinking buddy and friend with benefits, Doors frontman Jim Morrison.

“He had extremely high blood pressure,” the now 76-year-old actress told Fox News.

Stewart is best known for portraying Miss Beadle on “Little House on the Prairie."

“He had rheumatic fever as a child and he had an enlarged heart," she added. "And his face was always beet red. You know, blood pressure red. And I think that’s what probably killed him. He was in the bathtub, probably in hot water. He’d probably been drinking as he always did. And his heart gave out.”

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Before Stewart found fame with the western drama, which ran from 1974 to 1983, she owned a clothing store called The Liquid Butterfly, which was located across from Elektra Records in California, the label that the rock band was signed under. In her recently published memoir, titled “Little House in the Hollywood Hills,” she recalled how Morrison frequently spent time at her store where they became fast friends.

“We’d go sit at a bar [after work] and quite often I had to take him home because he overdid it a lot,” she explained.

When Morrison was arrested in 1969 for indecent exposure at a Florida concert, he turned to Stewart for support. They drove up the Pacific Coast Highway and found themselves exploring Hearst Castle.

Stewart chronicled their trip on video, and they'd frequently unwind with alcohol. He would drop her off in Los Angeles before he escaped to Paris. It would be the last time the duo would see each other. Just six month after their initial encounter, Morrison was found dead in 1971 at age 27.

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“I don’t know what the official report was on how he died,” she said. “But I do know, I never saw him with a drug. Ever. I never even saw him smoke marijuana. Ever. He drank. He drank heavily. It’s my theory that they wouldn’t have found drugs in his system.”

Courtesy of Charlotte Stewart (A still of Charlotte Stewart opposite co-star Elvis Presley in their film, "Speedway.")

In 1968, Stewart would also become a confidant to another music icon: The King. She briefly appeared in the film “Speedway” opposite Elvis Presley, which sparked a brief friendship.

“As soon as we were done with the first shot, he said, ‘You wanna talk?’ I was shocked. He pulled up two chairs together, we sat down, he took my hand and then he began to tell me about his mother,” revealed Stewart. “He talked about Gladys, how much he missed her, how when he was in the army, they wouldn’t let him go see her when she was dying… It wasn’t like he was flirting. He was just being very sweet. He could not have been nicer.”

One person who didn’t impress Stewart was Bill Murray.

“Quite frankly, that was a one night stand,” she said.

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The actor, who was appearing in a new sketch comedy show titled “Saturday Night Live” in 1975, used his popularity to help Stewart and her friend get in a local club.

Courtesy of Charlotte Stewart (A candid shot of Charlotte Stewart in costume as Miss Beadle on "Little House on the Prairie.")

“Of course they let Bill Murray in,” she said “We were drinking, dancing and then he came home with me. What can I tell you? And I never saw him again! I wasn’t interested in being anything more than fun. But I thought it was kind of rude of him to just stay the night with me and then never speak to me again.”

But Stewart had other troubles to worry about. After her time as a schoolteacher came to an end on “Little House,” she found herself addicted to drugs and alcohol, as well as facing homelessness.

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“Everybody was doing drugs,” she said. “You’ll just go to a party and somebody will go, ‘Hey, you want a sniff?’ I thought at the time it was just what everybody else did… My business manager had been doing drugs... The next thing I knew, my money was gone. He put it all up his nose. My mortgage had not been paid. I lost my house… I had money and then I didn’t. I’m just really lucky to be alive.

Courtesy of Charlotte Stewart (Charlotte Stewart with David Lynch.)

Stewart said it was her niece who prompted that journey to sobriety.

“She told me what a mess I was in a letter,” she explained. “It broke my heart and woke me up at the same time… I entered a recovery program that really turned my head around. I’m still going to meetings and I’m very grateful.”

By 1984, she sought help and slowly began rebuilding her life again, including accepting a role on the 1990s series “Twin Peaks.”

These days, Stewart is happily keeping busy. She still tours with her “Little House” cast across the country where she meets devoted fans. She’s also set to appear in the reboot of “Twin Peaks,” which debuts on May 21st.

Not only has she gotten married nearly two years ago to “a dear old friend,” she also credited former “Little House” cast-mate Alison Arngrim for encouraging her to publish a tell-all.

“Let’s face it, I have to stay busy,” she added. “I love to read, but I can’t spend my days reading or shopping. I work every day and prefer it that way.”