PRINCESS Diana's mother was last night seriously ill in hospital with an incurable and advanced brain disease.

Doctors were treating Frances Shand Kydd as the row raged over the screening of pictures of her dying daughter on TV.

The 68-year-old was admitted after her health deteriorated. Worried son Earl Spencer and his sister Lady Sarah McCorquodale arrived at the hospital in Oban yesterday. Sources admitted staff were "concerned" about her condition. One local said frail Mrs Shand Kydd has rarely been seen in recent weeks outside her home on the remote Scottish island of Seil.

And when she does she is in a wheelchair and always accompanied by a helper.

She uses a walking frame to get about inside the house.

The resident added: "The deterioration in her health has been quite dramatic over the last year. Everyone has noticed it.

"One day she seemed to be quite spry and able with her walking stick, the next she was in a wheelchair unable to get about.

"Anyone who knew her before is shocked when they meet her.

Casually dressed but looking haggard, Earl Spencer emerged from the Lorn and Island District Hospital at 7pm with Lady Sarah.

The grim-faced and clearly concerned pair chatted together in the car park before leaving.

Mrs Shand Kydd was admitted to the small hospital on Friday.

She is believed to be suffering from an incurable brain disease which she has been battling for some time. It is now thought to be advancing rapidly.

The hospital confirmed she is a patient there but a spokesman added: "We have no comment." Clarence House issued a statement on behalf of Princes William and Harry.

It said: "This is a private family matter and not something we would comment on."

Diana's other sister Lady Jane Fellowes is not thought to have visited Mrs Shand Kydd since her condition worsened last week.

The family's concern for their mother's health comes amid the row over pictures broadcast in the US showing Diana's dying moments after a Paris car crash.

Hours earlier Earl Spencer had blasted American TV bosses for broadcasting the shots.

Last night it was not known if Mrs Shand Kydd was aware of the sickening stunt by the CBS network. Her condition has left her struggling to walk or speak.

Family members have begged her to move from her home on Seil.

But she has been determined to stay in the community which supported her during the darkest days of her daughter's death.

She has insisted on remaining there - even if it means being on her own.

Her house is fitted with a host of hi-tech security devices and locals remain very protective of her.