She eventually succeeded in switching it off on the second attempt.

Doctors resuscitated Hilal K when they realised her machine had been switched off, however she later died from complications.

Hilal’s heartbroken daughter Sadet, 48, said: "My mother had been in hospital for a week, after she was diagnosed with heart fibrillation and anaemia.

"While she was in the clinic, she was infected with Covid.

"She was already on the oxygen machine when she was moved to the Covid ward.

"I was with her until 7pm on the day she died, and she was very tired, she slept most of the time.

"My mother had to be resuscitated. She almost died. I don't understand how she could have done this to my mother."

Shortly after Sadet left, Hatun is said to have got out of bed and switched off the oxygen as it was disturbing her sleep.

Hospital staff quickly noticed and warned her that she should not do it again as the "vital measure" was keeping her neighbour alive. Yet an hour later, around 9pm, she reportedly switched it off again.

The daughter criticised the clinic for leaving the other woman in the ward with her mother after her first attempt to turn off the oxygen.

A hospital spokesman confirmed the incident but said that it was in the hands of the public prosecutor, and they are not able to provide any more information.

Prosecutors in Mannheim say the patient sharing her room -named only as Hatun C, 72 - is being held in custody while they examine the case.

A spokesman said: "Investigations in this case are ongoing."