Rachel Kelly saw the father she adored turn from a dignified man, elated at her sister's wedding earlier this year, to a shattered, uncommunicative figure.

The quietly-spoken 30-year-old told the Hutton Inquiry into the circumstances of the death of Dr David Kelly about her close relationship with her father, an expert in biological weapons.

They spoke daily on the phone and often walked together in the Oxfordshire countryside, where they both lived. Her voice trembled as she spoke of the day she saw her strong father suddenly in need of her care and support.

She, like her mother, gave her evidence to the inquiry via a video link rather than face the packed courtroom.

As reported in the late edition of yesterday's Oxford Mail, her mother Janice had told Lord Hutton that her husband had felt "totally let down and betrayed" by the Ministry of Defence after officials released his name to journalists. Mrs Kelly, 58, from Southmoor, near Abingdon, said she and her husband were watching a TV news report about the Iraq arms dossier on July 8 when Dr Kelly first told her he was a possible source of the BBC's report alleging the Government had "sexed up" the dossier.

She said Dr Kelly had seemed "desperately unhappy about it".

Rachel Kelly, describing a meeting with her father ahead of his appearance before the House of Commons foreign affairs select committee two days before his death, said: "There was a really strong expression on his face that really shocked me, and I was quite distressed to see the hurt I could see in his face.

"There was a lot of distress and anxiety, perhaps a little bit of humiliation seeing his daughter for the first time since all this news about work had broken."

Miss Kelly said her father had tried to put on a brave face. But for once he could not hide his emotions - a rarity in a family that, while close, was not given to displays of emotion.

She added: "I love my father very much. As his daughter I was very concerned to see this vulnerable emotion. She added: "I love my father very much. As his daughter I was very concerned to see this vulnerable side of him."

"The moment passed and I was aware that he seemed very gentle, more child-like, and I was very conscious that our roles were reversed and that I needed to look after him and he needed to be looked after."

Her mother had told the inquiry that Dr Kelly was "not an easy man to support" and their daughter appeared to feel the same constraint. She said she had not wanted to "compromise his dignity" and this had, perhaps, prevented her from giving him more help.

But she, like the rest of her family, were deeply shocked at the change in a man who just months earlier had been "in his element" at the wedding of Rachel's twin sister, Ellen.

RSPB worker Miss Kelly said she was aware her father was already considering taking early retirement from the job he had previously loved.

He had seemed exhausted and was "under immense pressure" at work, but Miss Kelly said she did not think "for one moment" that her father could be embroiled in the row between the Government and the BBC.

But a chance reference to Alastair Campbell's criticisms of the BBC triggered a reaction which had shocked her as he seemed to start at her mention of the name.

"His reaction alarmed me," she said. "He just seemed to have the world's pressures on his shoulders."

Miss Kelly, like countless witnesses before her at the Hutton Inquiry, spoke of her father's outward impression of composure as he prepared for his appearance before the Foreign Affairs Select Committee.

But unlike so many of Dr Kelly's colleagues and superiors she was able to see beneath his calm exterior.

Miss Kelly's voice shook again as she described how her father had been questioned by the FAC, a grilling which had led him to call one of his inquisitors "an utter bastard".

It was a rare outburst from the weapons expert and his daughter's behaviour seemed more typical of the family when she refused to name the MP, saying he had suffered enough adverse publicity.

Her condemnation was more subtle.

Her sense of disappointment in the system which had caused her father such suffering was clear as she said she had expected a Select Committee to be "perhaps something quite gentlemanly".

And her final words to the inquiry kept that strength of feeling.

Miss Kelly said: "My heartfelt wish is that as a result of your inquiry, my Lord, that people will learn from the circumstances surrounding my father's death and show more compassion and kindness in future to those around them.

"My sisters and I love my father very much. We are immensely proud of his achievements, his love to us is immeasurable and we will always miss him.