Warning: Distressing content. A newly released death certificate has confirmed the cause of death of Martin Short’s daughter, Katherine Hartley Short, one week after her sudden passing.

Martin Short is heartbroken after his daughter Katherine Short died.Martin Short is heartbroken after his daughter Katherine Short died. Credit: AAP

Warning: Distressing content

Martin Short’s daughter, Katherine Hartley Short, died from a self-inflicted gunshot wound to the head, according to a newly released death certificate issued one week after the social worker’s sudden passing.

Martin Short says daughter Katherine was 'beloved by all' after her death at 42

The document, released by the Los Angeles County Department of Public Health on Tuesday and obtained by TMZ, confirmed the cause of death and noted that her remains have since been cremated. Katherine died by suicide on February 23 at the age of 42.

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News of her death prompted an outpouring of condolences for the Short family, with the actor’s representatives confirming the tragedy in a statement shortly after her passing.

“It is with profound grief that we confirm the passing of Katherine Hartley Short,” a representative for the Only Murders in the Building star shared.

“The Short family is devastated by this loss, and asks for privacy at this time,” they added.

“Katherine was beloved by all and will be remembered for the light and joy she brought into the world.”

Emergency responders were called to Katherine’s Hollywood Hills home on the evening of February 23. The Los Angeles Fire Department confirmed crews had “responded to a reported shooting” at the residence at about 6.41pm, where the “death of a female” was reported.

Law enforcement sources later said Katherine was found inside the home behind a locked bedroom door, with a gun and a note reportedly located nearby. Authorities were contacted after a close friend raised the alarm, telling police Katherine had not been heard from for about 24 hours.

Neighbours described the social worker as a largely private person, though several said she was friendly and approachable.

“Katherine was a private person, but that doesn’t mean she wasn’t friendly,” one neighbour told Us Weekly.

“She was quite outgoing.”

Although details surrounding her mental health remain unclear, reports suggest Katherine had obtained a service dog in recent years to help manage an unspecified mental illness.

Katherine was the eldest of three children adopted by Short and his late wife, Nancy Dolman. The couple adopted Katherine in 1982 and later welcomed sons Oliver Patrick, now 39, and Henry Hayter, 36.

Dolman, a Canadian actress, died from cancer in 2010 at the age of 58.

Katherine legally changed her surname to Hartley in 2012, though she remained close to her family.

Short has largely kept a low profile since the tragedy. The 75-year-old comedian postponed a series of comedy shows he was scheduled to perform alongside longtime collaborator Steve Martin following his daughter’s death and was also absent from the Screen Actors Guild Awards earlier this week.

He has not made any public comments beyond the statement released by his representatives.

Lifeline: 13 11 14.

Young people seeking support can phone beyondblue on 1300 22 4636 or go to headspace.org.au.

If you or someone you know needs help, phone SANE Australia Helpline on 1800 18 SANE (7263).