Actress Demi Moore suffered convulsions and seemed only semi-conscious after smoking an undisclosed substance before being rushed to hospital earlier this week, according to the tape of a medical emergency call released on Friday.

She smoked something, it's not marijuana but it is similar to incense. She seems to be having convulsions of some sort, a female friend of Moore told emergency services when calling for an ambulance on Monday.

She has been having some issues. I don't know what she has been taking, another woman at Moore's house that night told the 911 dispatcher. Moore was also described as burning up, unable to speak and semi-conscious before help arrived at her Beverly Hills mansion.

The tape shed the first official light on the emergency that sent recently-separated Moore to the hospital, and later to seek treatment for what her spokeswoman has described only as exhaustion.

Los Angeles officials said portions of the tape recording had been edited for privacy and to remove references to specific substances.

Celebrity website TMZ.com has reported that one of the friends at Moore's home on Monday told paramedics the actress had been inhaling nitrous oxide -- a substance also known as whip-its or poppers that gives users a high by briefly depriving the body of oxygen. The substance was not mentioned on the version of the tape recording released to the media.

The Ghost and G.I. Jane actress, 49, filed for divorce from husband Ashton Kutcher, 33, in November after the Two and a Half Men Star had a widely publicized fling with another woman.

Her gaunt appearance in paparazzi photos over the last few months has raised alarm bells in the celebrity media.

Her spokeswoman said on Tuesday Moore had decided to seek professional treatment for exhaustion and (to) improve her overall health because of stress. Moore's representatives have declined to give any details or comment further on her problems.

Moore and Kutcher were married for six years and their 16-year age gap made them the subject of constant media fascination.

Kutcher returned to Los Angeles from Brazil on Thursday, refusing to comment to the media about Moore.

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