A nurse who worked for Professor Stephen Hawking for 15 years has been suspended over allegations of "serious" misconduct concerning his care.
The move was taken at a secret tribunal where the scientist's immediate family lodged a complaint which prompted a long investigation into 61-year-old Patricia Dowdy, the Mail on Sunday has learned.
Details of the case and the type of disciplinary charges against have been suppressed by the body which regulates nursing.
The public and the media have been banned from the hearing because of the serious allegations being made against her, which have never been heard by the public.
Dowdy was suspended by the Nursing and Midwifery Council (NMC) when the claims surfaced.
The "substantive" hearing is ongoing behind closed doors and the charges are likely to never be disclosed to the public.
The nurse from Ipswich, Suffolk stopped working for Hawking two years before he succumbed to motor neurone disease in March last year at age 76.
When the Mail On Sunday asked the nurse about the allegations, Dowdy said: "This is all very upsetting. Can I just say 'no comment' at the moment? I'm not supposed to talk to anyone."
A source with knowledge of the case said the charges against the nurse were "pretty serious" but declined to discuss the matter further.
In 2004, Hawking's second wife, Elaine Mason, was accused of abusing her husband by 10 nurses who cared for him.
It is not known if Dowdy was among those who made statements to police or if that case is connected to the ongoing hearing.
Hawking had been confined to his wheelchair since he was 30 and was looked after by a rotation of private nurses and carers paid for by Cambridge University, where he was a mathematics professor.
Dowdy was often seen by his side.
Last night, a spokesman for the family said they did not wish to comment on the NMC hearing but said: "The past year has been a very distressing time for us."
The NMC maintained it was not intending to hold more hearings behind closed doors.
It said: "Hearings will usually take place in public. In some cases, including this particular case, there are reasons why this doesn't happen, due to the health of those involved. We will continue to give full reasons for the decisions we take so there is transparency about what steps have been taken to protect the public and why."